Luminous Landscape Forum

Raw & Post Processing, Printing => Digital Image Processing => Topic started by: Dave Gurtcheff on June 21, 2013, 03:22:06 PM

Title: PK Sharpener Question
Post by: Dave Gurtcheff on June 21, 2013, 03:22:06 PM
Hello all:
My usual workflow is to shoot RAW, and use either DXO or ACR to process the files. I then open in Photoshop (currently CS6), and do my adjustments (burn, dodge, Levels, rubber stamp, etc). When finished, and still at native resolution, and NO sharpening applied, I save it as a master. If I get a print order, my work flow has been: Rename the file such as "24"x32" sharpened file XXXX". I then apply PK Capture Sharpener. I then resize to the print size. Last I apply PK output sharpener. I recently had a print order for a 24"x32" image made from a Pentax 645D file. I printed it at 240 ppi. I somehow LOST the master file (DUH!!). No problem if all my prints were to be that size, but I just filled an order for a 17"x23". The image had already been sized and sharpend as a 24"x32". What I did was reduce the image size in PS to 17"x23" WITHOUT resampling down so the image was now 338.3 ppi. I printed it and it somehow does not seem to have the same "punch" as the larger print. Should I maybe have downsized to 240 ppi in PS by down sampling using the selection which says "best for reductions"?
Any advise short of "Don't lose your master"?
Thanks
Dave in NJ
Title: Re: PK Sharpener Question
Post by: texshooter on June 21, 2013, 04:41:43 PM
Did you try applying more output sharpening?
Title: Re: PK Sharpener Question
Post by: Schewe on June 21, 2013, 06:22:25 PM
What I did was reduce the image size in PS to 17"x23" WITHOUT resampling down so the image was now 338.3 ppi. I printed it and it somehow does not seem to have the same "punch" as the larger print. Should I maybe have downsized to 240 ppi in PS by down sampling using the selection which says "best for reductions"?


You should have rerun PKS after the resize without resampling because the sharpening is based on the actual PPI resolution. So, the difference between 240 and 338.3 had the impact on the sharpening as you've seen.
Title: Re: PK Sharpener Question
Post by: Dave Gurtcheff on June 22, 2013, 01:24:34 PM
Thank you Jeff. That is very helpful information. I am now reading The Digiat Negative, and find it very helpful.
Dave
Title: Re: PK Sharpener Question
Post by: PhotoEcosse on June 22, 2013, 02:40:38 PM
If you are interested in sharpening, take a look at this lesson by, probably, the world's greatest authority on the matter. His conclusion, briefly, is that most software has got it totally wrong (or worse).

http://guygowan.com/focus/

Title: Re: PK Sharpener Question
Post by: Schewe on June 22, 2013, 03:54:15 PM
...probably, the world's greatest authority on the matter.

He's a lengend in his own mind...I've seen a couple of his videos and he spends more time pontificating than actually teaching. But, by all means, make up your own mind. He's like an English Ken Rockwell.
Title: Re: PK Sharpener Question
Post by: Schewe on June 22, 2013, 05:03:01 PM
His conclusion, briefly, is that most software has got it totally wrong (or worse).

OK...that's an hour of my life I'll never get back...but I had to see it for myself (kinda like slowing down to look as a car crash on the highway).

He doesn't really understand the genesis of unsharp masking–which was an analog method of taking an image and making a blurred mask version to be combined with the original to increase the edge contrast and the accutance. It started not with scanners but with process cameras to make sharper film separations...

He likes to wave his hands and tout his "magic" but he doesn't really seem to drill down on anything unless you pay your money and join his inner circle. The problem is, his 'magic' isn't really magic, it's simply techniques...and these techniques are pretty easy to discover for oneself. So, I won't be joining Guy's inner circle any time soon :~)

Guy doesn't understand how to use Camera Raw's sharpening controls that he dismisses. He dismisses the Unsharp Mask filter in Photoshop (even though the controls actually do a digital version of the analog USM very accurately). He thinks Camera Raw and Lightroom are "useless" for sharpening and color correction...hum, I wonder what Guy thinks of Thomas Knoll and Eric Chan...I have enormous respect for both of them, and not so much for Guy.

But hey, that's just me...I know a lot about sharpening...worked with Bruce Fraser to develop PhotoKit Sharpener...licensed our output sharpening for Lightroom and Camera Raw and consulted with Thomas (and Eric) on the ACR/LR capture sharpening.

But, if you want to drink Guy's Kool-Aid, you go right ahead...


Title: Re: PK Sharpener Question
Post by: ButchM on June 22, 2013, 05:58:30 PM
... probably, the world's greatest authority on the matter.


No, I think that would be Bruce Fraser. Even in absentia.
Title: Re: PK Sharpener Question
Post by: texshooter on June 22, 2013, 06:24:05 PM
Guy has a point though. Why doesn't Photoshop have a wang bar that applies different degrees of sharpening to shadow and highlight pixels?
Title: Re: PK Sharpener Question
Post by: Schewe on June 22, 2013, 06:34:28 PM
Guy has a point though. Why doesn't Photoshop have a wang bar that applies different degrees of sharpening to shadow and highlight pixels?

It does, it's called Smart Sharpen, with the advanced tab selected...course Guy hates Smart Sharpen too...thinks it's useless.
Title: Re: PK Sharpener Question
Post by: sniper on June 22, 2013, 06:37:30 PM
No, I think that would be Bruce Fraser. Even in absentia.
And of course our very own Jeff Schewe, and personally I doubt theres many know more about the subject of sharpening than Jeff.
Title: Re: PK Sharpener Question
Post by: Schewe on June 22, 2013, 06:44:32 PM
Guy spends 80-90% of the hour long preso denigrating the tools and the engineers who have created Photoshop, Camera Raw and Lightroom. He spent a small amount of time actually talking about sharpening...but it was funny, I don't know how many people would catch it, but about 3/4 of the way through after the discussion of "Curves" and how he targets what he calls a "proportional mask" The layer blending options flashed on screen briefly before he grabbed it and moved it off screen...seems he didn't really want to show that. Know why? that's how you can target the various levels where a sharpening layer can be applied using the Blend If sliders...

So, let's see...he likes to use Unsharp Mask at 500 amount and 2 pixels...then me magically uses a proportional mask to apply the sharpening...Uh huh. Not particularly enlightening, is it? You have to pay to join the inner circle and learn the magic.
Title: Re: PK Sharpener Question
Post by: texshooter on June 22, 2013, 07:00:51 PM
Are the fuzzy before  images on the left in Guy's demo the product of Camera Raw's default sharpening? I don't know what he's comparing his results to. If the left shots are completely unsharpened, of course his work is draw-dropping good by comparison. But isn't the unsharp mask technology becoming outdated now that we have deconvolution-based sharpening tools?
Title: Re: PK Sharpener Question
Post by: Schewe on June 22, 2013, 07:08:05 PM
Are the fuzzy before  images on the left in Guy's demo the product of Camera Raw's default sharpening?

Actually, if you were paying attention, he's showing the before/after images in Aperture, not LR and he doesn't say whether on not any sharpening was applied by Aperture to the before images although based on the softness, I'm assuming he's turned off any sharpening so his after looks better. He only opened Camera Raw once to denigrate the controls. He seems to really, really hate Lightroom.

Just to be perfectly clear, Guy may know some stuff...I don't doubt that. The biggest problem I have with somebody like this is the constant harping on how BAD all the software is. He promotes himself by denigrating the the very tools he's using. And his Focus teasers are simply self-promotional tools to get you to pay to join and learn the real stuff–which since he's not a software developer is simply using Photoshop's own toolset that anybody can learn how to use. It's not like he's developed any special algorithms or plug-ins himself...
Title: Re: PK Sharpener Question
Post by: Schewe on June 22, 2013, 07:11:00 PM
And of course our very own Jeff Schewe, and personally I doubt theres many know more about the subject of sharpening than Jeff.

Thanks for the kid words...but most of what I've learned I learned from Bruce and the work I've done after Bruce passed away. But yes, I will admit I do know a lot thanks to working with the likes of Thomas Knoll and Eric Chan on ACR/LR sharpening–which Guy thinks sucks. Funny, I bet I could teach Guy how to use ACR/LR's sharpening pretty well but I seriously doubt he would have any interest–and it would kill off a lot of his "magic".
Title: Re: PK Sharpener Question
Post by: BartvanderWolf on June 22, 2013, 08:30:54 PM
If you are interested in sharpening, take a look at this lesson by, probably, the world's greatest authority on the matter.

Hi,

Well, that depends on who is calling whom an authority (for a blind person, a Cyclops seems to be a genius). 

Quote
His conclusion, briefly, is that most software has got it totally wrong (or worse).

Actually, he is right, but for the wrong reasons. He does have a point about the almost(!) brain-dead controls we have to cope with in many applications.

Unfortunately in this time and age, not a single time did he mention deconvolution (which might be a good thing if he doesn't understand what that is about). It's a basic procedure to anybody even remotely familiar with the physical properties of digitized image data (from a CCD/CMOS sensor, or even from an analog scanning tube). I do understand where he's coming from, with a scanning operator's background, and from that limited angle of view, he is correct, modern controls (wang-bars) do suck.

However, anybody who is even slightly introduced to digital signal processing (DSP), and could be (http://www.dspguide.com/pdfbook.htm) for free, should know that digitized image data offers a different toolset to reduce Capture deficiencies (residual lens aberrations and diffraction, and DOF blur), which will impact the entire(!) spatial frequency range of the Modulation Transfer Function (MTF). In addition to that (capture sharpening in a gamma adjusted, or not, colorspace), there are several methods to address output sharpening, and the better ones do address variable sharpening at different tonality or local contrast ranges.

For quite some time already, I've been an advocate for luminosity blend-if layers, to control potential clipping artifacts from poorly designed sharpening tools (see the dialog box below which only suggests a starting point for adjustment):

(http://bvdwolf.home.xs4all.nl/main/downloads/Non-clipped-sharpening.png)

Proper deconvolution sharpening shouldn't even produce clipping (or noise amplification, if avoidable), but the current sharpening controls usually do not offer any control (or even really useful user guidance/feedback) to that (clipping) effect.

Cheers,
Bart
Title: Re: PK Sharpener Question
Post by: PhotoEcosse on June 23, 2013, 09:23:50 AM
But it's not just sharpening that the guy can help us with. He also explains how most Raw converters have got it seriously wrong:

http://guygowan.com/focus/focus1.php

(Unfortunately, once again, he does take rather a long time to cover the ground.)
Title: Re: PK Sharpener Question
Post by: BartvanderWolf on June 23, 2013, 11:16:39 AM
But it's not just sharpening that the guy can help us with.

Hi,

I'm not so sure he's really helping with sharpening, because he seems stuck in old fashion UnSharp Masking techniques. He does manage to use those limited tools effectively. But there are fundamentally better ways of getting there.

Quote
He also explains how most Raw converters have got it seriously wrong:

Again, he does have a point, but then he also doesn't seem to use ACR/Lightroom optimally. He is correct that the lack of indication of how much recovery has been applied in ACR/LR, doesn't help to use the controls to set to the best values (of which there are plenty to get wrong). There is also an under-the-hood exposure shift encoded which is different for various cameras. That all doesn't help to understand what's going on.

That's one of the reasons I prefer Capture One or RawTherapee for Raw processing, there are fewer hidden 'adjustments'. He is correct that Highlight recovery tends to kill highlight quality, but he seemingly advocates to overexpose and pull exposure to reduce clipping and improve the shadow detail quality, which is very risky without full control over how the overexposure is brought back into range (RawTherapee allows to do that, and it's better at Deconvolution Capture sharpening). Maybe Aperture also does that better, which could explain why he likes that better for those on a Mac.

His kind of snarky and critical attitude towards Adobe (which seems to be effective in upsetting some) is to be seen as a bit of posturing, to sell his personal views as gospel. The fact that he needs to do that is also a bit telling, but he also does make a few good points.

Cheers,
Bart
Title: Re: PK Sharpener Question
Post by: texshooter on June 23, 2013, 03:45:55 PM
I read somewhere that Deconvolution sharpening (E.g., Focus Magic, Topaz InFocus) is best for "resolution" sharpness when used for capture or output sharpening, and Unsharp Mask sharpening (e.g., Photokit Sharpener, Nik Sharpener Pro) is best for "acutance" sharpness when used for creative sharpening. What say you?
Title: Re: PK Sharpener Question
Post by: BartvanderWolf on June 23, 2013, 04:30:12 PM
I read somewhere that Deconvolution sharpening (Focus Magic, Topaz InFocus) is best for "resolution" sharpness when used for capture or output sharpening, and Unsharp Mask sharpening (Photokit Sharpener, Nik Sharpener Pro) is best for "acutance" sharpness when used for creative sharpening. What say you?

Hi,

That's essentially correct.

The Capture process is inherently blurry, because of optical imperfections, diffraction, and defocus. Then there is the influence of usually an Optical Low-Pass Filter (OLPF), and a somewhat square area sampling aperture of the sensel. There is also an effect from not sampling all the color-channels at each sensel position. Combined these produce a Gaussian type of blur that can be effectively improved by Deconvolution. This assumes there is little camera shake or vibration, which has a different blur signature, but can also be reduced by Deconvolution.

Output usually involves resampling the image data to match the printer driver's native resolution, or downsampling for display purposes. Resampling creates a certain level of blur, and that also can be effectively reduced by deconvolution.

In between these Capture and Output Deconvolution steps that actually increase resolution by removing the blur, one can target different things that involve the impression of sharpness, acutance, by boosting or reducing local contrast. But there are better tools available than simple USM based edge contrast boosters, even if they use blend-if layers and masks.

In a simple form one could think of Dodging and Burning, or High-Pass filtering which addresses specific spatial frequencies, but more efficient tools target multiple spatial frequency bands at the same time (e.g. Topaz Detail). There are also new developments in addressing Clarity at different ranges of contrast (e.g. Topaz Clarity), and all sorts of tonemapping tools for locally compressing or expanding tonality (e.g. ACR/LR process 2012, or even better Topaz Adjust which allows Adaptive Exposure adjustment throughout the image in an adjustable number of zones).

There is one type of (De)convolution (de)blurring that could be done in this Creative 'Sharpening' stage as well, and that involves the adjustment of DOF blur, but that is a complex procedure because the level of blur changes with distance, and the depth clues are to a large extent no longer available unless a depth map can be constructed.

Cheers,
Bart
Title: Re: PK Sharpener Question
Post by: Schewe on June 23, 2013, 06:28:50 PM
But it's not just sharpening that the guy can help us with. He also explains how most Raw converters have got it seriously wrong:


This was actually the first tutorial (if you can call it that) I saw from Guy...and Guy has it seriously wrong. He doesn't know how to use Camera Raw (nor Lightroom). Which is not atypical behavior coming from so called Photoshop Experts. When all you have is a hammer, everything looks like a nail.

Guy seems to know Photoshop (at least to a degree) but he doesn't know Camera Raw. He gets a lot wrong in this video...but the major disconnect is he doesn't really understand raw linear captures. The curve he drew on his whiteboard was more like a D Log H curve, not a raw capture curve–which is linear or a gamma curve of 1.0 or actually a 45º line from the lower left to upper right.

I'm not really sure Guy actually knows what "highlight recovery" actually is–recovery in ACR is extracting textural information from the highlights when 1 or 2 of the channels are clipped. Recovery interpolates the missing 1 or 2 channels of color data that are clipped and provides useful texture (not useless as Guy claims). Yes, recovery is an interpolation...and in PV 2003 and 2010 it could produce color problems. That was pretty much eliminated in PV 2012.

Process Version 2012 doesn't actually apply any "recovery" by default–recovery only kicks in with minus Exposure, Highlights and Whites adjustments and recovery is much improved. What PV 2012 does do is an image adaptive auto-ranging that keeps near clipping from clipping. If all three channels clip, it indicates total sensor saturation and there's nothing one can do to "recover" from that. What PV 2012 does is more a tone mapping function and not a recovery operation. Yes it has an impact on the tone mapping of highlights (and shadows BTW) and yes, PV 2012 is much less likely to clip highlight data–which is actually a good thing, not a bad thing. How you handle the mapping is up to you. Not only do you have the Basic panel for tone mapping but you have the point curve editor which give very fine control over the highlights–if you know how to use it.

The example image of the house he showed could very, very easily be controlled in PV 2012 if he bothered to touch any of the other controls than Exposure...same deal on the wedding dress shot. He makes zero effort to actually use and of the vast array of tone mapping controls that ACR provides. Well, if you don't use the controls, yeah, well, your stuff will look like Guy's. Rather poor and he does a really good job of under-selling the ACR raw processing capability. Note, the demo of the girl and violin was processed in PV 2010 in ACR (with bad recovery, but note he didn't use PV 2012 with better recovery) and compared PV 2010 in ACR to Aperture...hum, one wonders why? Ah, of course, to make ACR look as bad as he can and promote Aperture as the best raw processor on the planet.

But the worst part of Guy's approach is that he is so dismissive and disrespectful of the tools he uses and the people who develop them. If he knows so much, why isn't he more involved in the development of the tools he uses? He claims he was a "consultant" to Adobe...but I've been involved with Adobe since Photoshop version 4 (that's PS 4, not CS4) and I had never heard about Guy until this year. So, I seriously doubt that Guy has had any direct involvement in the development of Photoshop nor Camera Raw/Lightroom. In light of his dismissive attitude, I would be very surprised that Adobe would want Guy's input...

But hey, don't take my word for it...go ahead and see what Guy has to say...if you are predisposed to dislike Camera Raw or Lightroom as a raw processor, Guy is talking your language...if you are a Photoshop "expert" and you want to ignore all the research and development of smart guys like Thomas Knoll and Eric Chan, by all means, do all your work in Photoshop and buy Guy's magic actions...go right ahead...I'll keep using ACR/LR on my work followed by a touch of Photoshop when needed.
Title: Re: PK Sharpener Question
Post by: jrsforums on June 23, 2013, 07:08:11 PM

Process Version 2012 doesn't actually apply any "recovery" by default–recovery only kicks in with minus Exposure, Highlights and Whites adjustments and recovery is much improved. What PV 2012 does do is an image adaptive auto-ranging that keeps near clipping from clipping. If all three channels clip, it indicates total sensor saturation and there's nothing one can do to "recover" from that. What PV 2012 does is more a tone mapping function and not a recovery operation. Yes it has an impact on the tone mapping of highlights (and shadows BTW) and yes, PV 2012 is much less likely to clip highlight data–which is actually a good thing, not a bad thing. How you handle the mapping is up to you. Not only do you have the Basic panel for tone mapping but you have the point curve editor which give very fine control over the highlights–if you know how to use it.



Jeff....not sure what you mean by not applying automatic "recovery"..??

Checking RAWs in RAWdigger shows that any highlight in LR greater than ~97% will have at least one channel clipped.

This is described in detail in George Jardine's article:  http://mulita.com/blog/?p=3358
Title: Re: PK Sharpener Question
Post by: Schewe on June 23, 2013, 07:40:19 PM
He also explains how most Raw converters have got it seriously wrong:

Oooops...I never watched Guy till the bitter end till this time. I caught him in a big fat lie.

He claims Adobe didn't develop Lightroom from the ground up, he claims Adobe bought Lightroom and only to compete against Aperture after Aperture came out. Nope, sorry Guy, that is a lie plain and simple. I've been involved in the development of Lightroom from the very, very beginning and I can assure you Adobe developed it from the ground up and developed in in the same time frame that Apple developed Aperture and that Adobe didn't "copy" anything about Aperture...you can read the real Lightroom development here (http://photoshopnews.com/2006/01/09/the-shadowlandlightroom-development-story/).

So, whatever credibility Guy may have had just went out the window...liar, liar, pants on fire :~)
Title: Re: PK Sharpener Question
Post by: jrsforums on June 23, 2013, 07:51:06 PM
Oooops...I never watched Guy till the bitter end till this time. I caught him in a big fat lie.

He claims Adobe didn't develop Lightroom from the ground up, he claims Adobe bought Lightroom and only to compete against Aperture after Aperture came out. Nope, sorry Guy, that is a lie plain and simple. I've been involved in the development of Lightroom from the very, very beginning and I can assure you Adobe developed it from the ground up and developed in in the same time frame that Apple developed Aperture and that Adobe didn't "copy" anything about Aperture...you can read the real Lightroom development here (http://photoshopnews.com/2006/01/09/the-shadowlandlightroom-development-story/).

So, whatever credibility Guy may have had just went out the window...liar, liar, pants on fire :~)

They did buy RawShooter about the time that LR was close to coming out.  Not sure if this was for the technology or the people...or both....but I believe the intent was to add to/improve LR.
Title: Re: PK Sharpener Question
Post by: Schewe on June 23, 2013, 09:36:05 PM
Just to be clear...I was at an initial product meeting about what would become Lightroom in my studio in Dec, 2002. Shadowland went through many iterations in 2003-2005 with the public beta of Lightroom shipping in Jan 2006–before Adobe bought Pixmantec in June 2006. Adobe bought Pixmantec to get one specific engineer...which sadly didn't work out. There were two Rawshooter controls that were added to Lightroom; Fill Light and Vibrance although the algorithms were totally rewritten.

Yes, Aperture 1 shipped before Lightroom...but anybody with any experience in software development would know you don't create a product from scratch in a few months...in fact, I know about the guy that started working on Aperture (the same guy that worked at Adobe on Premiere Pro and left to start Final Cut Pro) and Mark, the founding engineer on Lightroom were "friends" (a couple of companies removed). They both were working on the same database driven raw processing application solution at the same time.

So, for Guy to claim Adobe "bought" Lightroom and didn't develop it from scratch is an outright lie...
Title: Re: PK Sharpener Question
Post by: jrsforums on June 23, 2013, 10:04:16 PM
Just to be clear...I was just saying the RawShooter acquisition may have confused Guy's thoughts on LR's development.

...but I also agree that he is totally confused with what can be done in LR and the differences between PV2010 and PV2012.

He also was, unfortunately, trying to build mystery in his actions.  From some peeks in his videos it seems as if he was simply using BlendIf, Luminosity mask, and, probably, edge mask routines to do his "magic"

Much of these tutorials and actions were provide years ago, free, by Glenn Mitchell...still available, I think at "The Light's Right" site http://www.thelightsright.com/

Really enhanced luminosity masking techniques are available from Tony Kuyper http://goodlight.us/
Title: Re: PK Sharpener Question
Post by: daws on June 23, 2013, 10:24:36 PM
If you are interested in sharpening, take a look at this lesson by, probably, the world's greatest authority on the matter. His conclusion, briefly, is that most software has got it totally wrong (or worse).

http://guygowan.com/focus/

Regardless of his expertise or lack of it, what I find most fascinating about Guy is that the format of his spiel is similar to that of any number of self-proclaimed authorities in alternate archaeology, physics, psychology and spiritualism -- the pop gurus of Atlantis, cold fusion, New Age healing and paranormal investigations. The four giveaways are the glib use (often misuse) of technical terminology to create an air of authenticity, the bashing of establishment thought to project a character of truth-seeking and altruism (often with an implication of selfless martyrdom), the lack of established credentials and/or presence of questionable credentials, and always the push to self-publicize.

Title: Re: PK Sharpener Question
Post by: texshooter on June 23, 2013, 10:34:00 PM
Regardless of his expertise or lack of it, what I find most fascinating about Guy is that the format of his spiel is similar to that of any number of self-proclaimed authorities in alternate archaeology, physics, psychology and spiritualism -- the pop gurus of Atlantis, cold fusion, New Age healing and paranormal investigations. The four giveaways are the glib use (often misuse) of technical terminology to create an air of authenticity, the bashing of establishment thought to project a character of truth-seeking and altruism (often with an implication of selfless martyrdom), the lack of established credentials and/or presence of questionable credentials, and always the push to self-publicize.


It's called salesmanship.
Title: Re: PK Sharpener Question
Post by: Schewe on June 24, 2013, 12:20:37 AM
It's called salesmanship.

So, salesmanship includes lying? Salesmanship includes denigrating competing products? I suppose it does if you are a used car salesman (or a snake oil salesman).
Title: Re: PK Sharpener Question
Post by: Garnick on June 24, 2013, 10:32:23 AM
I'll be the first to admit that I'm certainly no expert on this subject as it pertains to the "Guy Gowan Show".  Most of my business is built around printing for local photographers, as well as fine art reproductions.  I rarely use ACR except to recover some image data in a particularly ornery file I've been presented with.  Due to the fact that one of my major customers(also a long time friend) is a devotee of Guy, I was finally inspired to watch one of his videos mentioned on a recent post in this thread.  I'm a big fan of Jeff's work and dedication to this industry, as well as his contributions to this forum and the videos he and Michael have produced.  It's been rather enlightening to read his replies here as usual.

Now back to my lack of expertise in ACR.  My aforementioned customer/friend was telling me about yet another "amazing" revelation he had found in one of Guy's recent vids.  Having waded through the Focus 02 video I am now trying to make my way through Focus 01.  I have just reached the part where he is talking about the shadow recovery function of ACR, LR etc and the house across the street that he shot a few minutes before recording that video.  I noticed that in ACR he had stepped back from 2013 to 2010 version in order to show the difference between the two versions when indicating the amount of highlight clipping.  My customer/friend was telling me a few days that Guy had recommended never using the 2013 version of ACR for that particular function because it isn't as accurate as 2010.  I thought I would throw this out to the folks here who are much more involved with the "science" of ACR than I am.  What are your thoughts on this function of ACR(clipping indicators) in v2013 as opposed to v2010?  I'd like to be able to put together a somewhat educated reply to my customer when he asks my opinion of Guy and his approach to ALL things digital, and the fact that his is the ONLY valid method on Planet Earth.  I guess I've tipped my hand here somewhat, but people who come on as the latest and greatest in that manner don't last long in my world.  When the only way of projecting one's so called expertise is to first slam every other possible method, and then pick little goodies from other sources that have been in existence for many years and pretend they were your own brainchild, not my cuppa.  

Gary                  
Title: Re: PK Sharpener Question
Post by: digitaldog on June 24, 2013, 11:42:41 AM
My customer/friend was telling me a few days that Guy had recommended never using the 2013 version of ACR for that particular function because it isn't as accurate as 2010.

Accurate? That's an easy buzzword to throw out but it's kind of meaningless without a through description of what is meant with some metric of inaccuracy (like the differences between a reference value and the output values is a dE of 1.3). So when someone says this is more or less accurate, without backing up the methodology used to come up with the conclusions, the hair's on the back of your neck, like mine should raise!
Title: Re: PK Sharpener Question
Post by: Garnick on June 24, 2013, 12:05:21 PM
Accurate? That's an easy buzzword to throw out but it's kind of meaningless without a through description of what is meant with some metric of inaccuracy (like the differences between a reference value and the output values is a dE of 1.3). So when someone says this is more or less accurate, without backing up the methodology used to come up with the conclusions, the hair's on the back of your neck, like mine should raise!

Thanks for that Andrew.  I assume you haven't seen the video I was referring to from the "Guy".  He has on screen a wedding shot wherein the brides white dress is of course lacking a lot of detail in order to maintain shadow detail throughout the rest of the image.  He then shows that although all of his clipping parameters are turned on there is no indication of any clipping in the highlights.  At that point he reverts back to v2010 in the "Process" tab and it shows a rather large amount of highlight clipping, which he proceeds to overcome with the "Exposure" slider.  It does seem rather evident that v2010 is for some reason indicating clipping where v2013 is not.  I'm not at all sure why that would be the case, so if you could provide an answer to that it would be much appreciated.  For me it's not so much a matter of metrics as perhaps a possible indication that v2013 is not indicating highlight clipping with the same degree of "accuracy" as was the case with v2010.  I'm not sure I am making any sense here at all, even though it somehow seems reasonable to me that v2013 may not be telling the whole truth as far as clipping is concerned.  Any further light you can shed on this would certainly be helpful.

Thanks again,
Gary   
Title: Re: PK Sharpener Question
Post by: bjanes on June 24, 2013, 12:07:16 PM
Accurate? That's an easy buzzword to throw out but it's kind of meaningless without a through description of what is meant with some metric of inaccuracy (like the differences between a reference value and the output values is a dE of 1.3). So when someone says this is more or less accurate, without backing up the methodology used to come up with the conclusions, the hair's on the back of your neck, like mine should raise!

Accuracy can not be defined without knowing a reference value for comparison. This guy might be using departure from scene referred values as an indication of inaccuracy. With PV 2010 one could obtain scene referred values by setting the sliders on the main ACR tab to zero and setting the point curve to linear. Obtaining scene referred values with PV 2013 is not straight forward since this version uses image adaptive algorithms that protect highlights. However, for rendering into an output space, one does not want linearity and the PV2013 controls give superior results with less work.

Bill
Title: Re: PK Sharpener Question
Post by: digitaldog on June 24, 2013, 12:13:11 PM
He has on screen a wedding shot wherein the brides white dress is of course lacking a lot of detail in order to maintain shadow detail throughout the rest of the image.  He then shows that although all of his clipping parameters are turned on there is no indication of any clipping in the highlights.  At that point he reverts back to v2010 in the "Process" tab and it shows a rather large amount of highlight clipping, which he proceeds to overcome with the "Exposure" slider.  It does seem rather evident that v2010 is for some reason indicating clipping where v2013 is not.

I still don't feel that's got anything to do with accuracy. There's a difference yes. The raw data is the same of course. The rendering controls between versions isn't. Neither can be said to be accurate or inaccurate IMHO. The correct statement would be "they are different". If you have a bias, you can attempt to prejudice others by suggesting one isn't accurate but again, that's not useful. There isn't clipping in the truest sense if the rendering controls bring back the data unclipped!
Title: Re: PK Sharpener Question
Post by: jrsforums on June 24, 2013, 12:48:28 PM
Thanks for that Andrew.  I assume you haven't seen the video I was referring to from the "Guy".  He has on screen a wedding shot wherein the brides white dress is of course lacking a lot of detail in order to maintain shadow detail throughout the rest of the image.  He then shows that although all of his clipping parameters are turned on there is no indication of any clipping in the highlights.  At that point he reverts back to v2010 in the "Process" tab and it shows a rather large amount of highlight clipping, which he proceeds to overcome with the "Exposure" slider.  It does seem rather evident that v2010 is for some reason indicating clipping where v2013 is not.  I'm not at all sure why that would be the case, so if you could provide an answer to that it would be much appreciated.  For me it's not so much a matter of metrics as perhaps a possible indication that v2013 is not indicating highlight clipping with the same degree of "accuracy" as was the case with v2010.  I'm not sure I am making any sense here at all, even though it somehow seems reasonable to me that v2013 may not be telling the whole truth as far as clipping is concerned.  Any further light you can shed on this would certainly be helpful.

Thanks again,
Gary   

In my limited, possibly slightly unscientific, testing, I seemed to see that PV2010 showed clipping about when only one channel was clipped.  Recovery would allow some of that to be pulled back (recovered), with differing degrees of success and texture.

2013, irrespective of what Jeff stated, does seem to apply a level of automatic recovery.  I am not sure at what level it stops nor how it determines the stop point.  Measurements in RawDigger indicate that one channel will clip at ~97%....between 97% and 100% (full clipping) can be more that 2 stops.  In that range, color accuracy and texture will diminish dependent on the amount of clipping/recovery success.  Best practice is not to clip any RAW channels.
Title: Re: PK Sharpener Question
Post by: bjanes on June 24, 2013, 12:55:01 PM

Neither can be said to be accurate or inaccurate IMHO. The correct statement would be "they are different". If you have a bias, you can attempt to prejudice others by suggesting one isn't accurate but again, that's not useful. There isn't clipping in the truest sense if the rendering controls bring back the data unclipped!

The raw data is either clipped or not. Highlight recovery does work within limits, but that does not mean the raw file was not clipped. The best tool to check for clipping is probably Rawdigger. PV2012 is not good for this purpose because of its image adaptive algorithms that protect the highlights. With ACR me own experiments indicate it is best to use PV2010 with a linear tone curve and take the baseline offset into account.

Bill
Title: Re: PK Sharpener Question
Post by: Schewe on June 24, 2013, 01:01:26 PM
At that point he reverts back to v2010 in the "Process" tab and it shows a rather large amount of highlight clipping, which he proceeds to overcome with the "Exposure" slider.  It does seem rather evident that v2010 is for some reason indicating clipping where v2013 is not.  I'm not at all sure why that would be the case, so if you could provide an answer to that it would be much appreciated.  For me it's not so much a matter of metrics as perhaps a possible indication that v2013 is not indicating highlight clipping with the same degree of "accuracy" as was the case with v2010.

PV 2012 (not 13 yet) takes an entirely different approach to tone mapping than PV 2013/2010. Where in PV 2010 the processing couldn't extract image texture in 2012 it can. So, yes, in PV 2010 the data was clipped in 2012 it isn't. PV 2012 was brought about due to research from 3 pretty bright guys (including Jan Kautz from University College of London, the other two guys are from MIT). You can read about the research in this article Magic or Local Laplacian Filters? (http://blogs.adobe.com/lightroomjournal/2012/02/magic-or-local-laplacian-filters.html). Note, it's pretty deep stuff...

The bottom line is that Guy is a Photoshop "expert" so it's in his best interest to tout his Photoshop skills and his actions. It's not in his best interests to learn to use and then teach how to do what he does in Camera Raw. You notice he always pulls Exposure down in ACR or Aperture then "fixes" the resulting dark image in Photoshop? Well, his before and after results are skewed because he's intentionally making the image look bad before coming along and fixing it in Photoshop. Why not just adjust the image in ACR? Because then he couldn't sell you his actions...

In all of his example images, he left image quality on the table by ignoring image optimization until opening the image in Photoshop. He denigrates Camera Raw as a way of inducing his viewers to ignore the functionality and capabilities of Camera Raw. Yes, when you pull Exposure 1.5+ stops, you are gonna need some heavy duty fixing in Photoshop. But that's the snake oil salesman doing that.

Up till tis recent go around I was will to consider Guy an eccentric...but no more. Not when he blatantly lied about the development of Lightroom and claimed Adobe copied Aperture. Nope...now I'm seeing him in a new light that is even more, uh, unfavorable.
Title: Re: PK Sharpener Question
Post by: Schewe on June 24, 2013, 01:44:13 PM
The raw data is either clipped or not.

Note that in Camera Raw, the clipping calculations are done in 8 bit based on the output color space set in Workflow Options. Also note there are 3 potential clipping indicators; holding down the option/alt keys when adjusting certain sliders, the on screen red for highlights and blue for shadows and the flashing triangle indicators on the histogram. Of the three perhaps the most accurate are the option/alt when moving a slider and the red/blue on screen indicator.

So, evaluating the differences between PV 2010 and 2012 in terms of clipping indicators being in 8 bit, it wouldn't surprise me that PV 2012 can (and does) get at more highlight texture detail that is not really clipped while PV 2010 shows the data as clipped.

When talking about "recovery", I think a lot of people get confused between recovery vs compression. PV 2012 does a lot of extreme highlight compression to mitigate clipping. Some people don't like that and you can work around that by using curves. When I think of recovery I think of the old Recovery algorithm in PV 2010. PV 2012 is NOT doing that sort of recovery...and PV 2012 doesn't suffer from the same color contamination that PV 2010 suffered from.

PV 2012 was originally designed for use in floating point HDR images...(see the Local Laplacian Filters article). It was adapted to work on non-HDR image in ACR/LR by the engineers and believe me, when I read the SIGGRAPH paper, my eyes rolled back in my head. I don't understand that stuff and never will.

But, I do know how to tell really smart people from not so smart people. I know Thomas and Eric pretty well and I've met Sylvain Paris (one of the authors of the paper) and they are really, really smart. I don't like the way Guy accuses Adobe of arrogance and denigrates the work of these guys...neither Thomas nor Eric are arrogant. OK, Mark Hamburg (the guy that started Lightroom and the second engineer to work on Photoshop) is a bit arrogant...but the engineers do this stuff to get the absolute best they can out of raw captures. They are not predisposed to back off on the raw processing and simply fix it in Photoshop.
Title: Re: PK Sharpener Question
Post by: PhotoEcosse on June 24, 2013, 02:35:49 PM
Hmmmm......

Glad I brought that stuff over here to get a second opinion.

Very illuminating.

(Apologies for forgetting that Americans don't quite grasp the concept of "irony". I'll stick one of those wee yellow sticky notes on my monitor to remind me. :) )

.
Title: Re: PK Sharpener Question
Post by: jrsforums on June 24, 2013, 03:33:54 PM
Note that in Camera Raw, the clipping calculations are done in 8 bit based on the output color space set in Workflow Options. Also note there are 3 potential clipping indicators; holding down the option/alt keys when adjusting certain sliders, the on screen red for highlights and blue for shadows and the flashing triangle indicators on the histogram. Of the three perhaps the most accurate are the option/alt when moving a slider and the red/blue on screen indicator.

So, evaluating the differences between PV 2010 and 2012 in terms of clipping indicators being in 8 bit, it wouldn't surprise me that PV 2012 can (and does) get at more highlight texture detail that is not really clipped while PV 2010 shows the data as clipped.

When talking about "recovery", I think a lot of people get confused between recovery vs compression. PV 2012 does a lot of extreme highlight compression to mitigate clipping. Some people don't like that and you can work around that by using curves. When I think of recovery I think of the old Recovery algorithm in PV 2010. PV 2012 is NOT doing that sort of recovery...and PV 2012 doesn't suffer from the same color contamination that PV 2010 suffered from.

PV 2012 was originally designed for use in floating point HDR images...(see the Local Laplacian Filters article). It was adapted to work on non-HDR image in ACR/LR by the engineers and believe me, when I read the SIGGRAPH paper, my eyes rolled back in my head. I don't understand that stuff and never will.

But, I do know how to tell really smart people from not so smart people. I know Thomas and Eric pretty well and I've met Sylvain Paris (one of the authors of the paper) and they are really, really smart. I don't like the way Guy accuses Adobe of arrogance and denigrates the work of these guys...neither Thomas nor Eric are arrogant. OK, Mark Hamburg (the guy that started Lightroom and the second engineer to work on Photoshop) is a bit arrogant...but the engineers do this stuff to get the absolute best they can out of raw captures. They are not predisposed to back off on the raw processing and simply fix it in Photoshop.

Jeff....I understand there is a lot of rolloff/compression at the highend in LR.

However, when you examine the RAW files for just about all files that have highlights above 97% in LR....at least one of the channels, often more, are clipped.

Whatever you want to call it, this is a level of autorecovery.  If it were not, the LR histogram would accurately reflect the clipping....or at least it should. 

You are big on saying people lie.  Why are you not attacking this lie?  It is at least a "white lie"....protecting people from using poor shooting technique/errors.  BTW...I like it and understand why it was put in....but would really like a true RAW histogram, so I didn't have to go off to RawDigger.

BTW...I think it is time to let up on Guy.  I don't like his "schtick" either, but getting his facts wrong does not necessarily make him a lier.  There have been lots of stories about LR development, including one where Adobe did, or was about to, kill it until they heard about Aperture.  I suspect there is more than one "true" story...depending on who you talk to and what they remember.
Title: Re: PK Sharpener Question
Post by: Dave (Isle of Skye) on June 24, 2013, 05:06:02 PM
I am not inside Guy's inner circle either, never have been and don’t intend to join, but having now watched the video link myself and which I found as equally entertaining as it was annoying, I think it is not that difficult to look past Guy’s hyperbole and work out the steps that Guy has put into his sharpening action, to achieve what he is suggesting is a more adaptive sharpening method, and which is probably based on an old method of sharpening via the channels and luminosity selections, but with a few updates and tweaks added - I imagine.

But for the sake of not throwing the baby out with the bathwater and to play a little bit of the devil’s advocate, I do think that Guy points out quite a few general truths about the standardised approach to sharpening, that most of us have relaxed into and now use without thought:

1 – Sharpening an image optically, by evaluations based on the screen, is not always the best method to sharpen an image, due to screen resolution and clarity of detail etc, and neither is it necessarily representative of the sharpening or acutance being applied to the actual data within the image.

2 – Sharpening an image optically and without regard to the output device, is also not the best way to achieve optimum output sharpening.

3 – Applying a ‘standard’ level of sharpening across all areas of the image, in the shadows, quarter tones, mid tones, three quarter tones and highlights equally, is again not the most effective way to produce the best sharpening of all areas within an image.

4 – Sharpening an image with wang bars (as Guy calls them), until the data in the most effected areas becomes too crunchy or haloed and then pulling back the wang bars to a level of acceptability as dictated by the worst affected areas, and without regards to the other areas that may require more sharpening, is also not the most effective way to sharpen an image.

5 – Adding more wang bars to a sharpening tool, can add unnecessary and misunderstood extra choices to the average user.

6 – Standard sharpening tools used in a standard way, are not sufficiently intuitive to allow the user to apply sharpening in a graduated or selective manner, based on the areas within each image that require more or less sharpening.

7 - Applying sharpening to each and every image through individual experimentation, is bound to slow down your workflow and provide you with inconsistent results.

8 – Basing the sharpening on the actual pixel data (tonality, colour and levels of luminosity) within each individual image, should provide a better method of sharpening, especially if it can be achieved and applied easily and automatically, yet still creating a flexible and graduated result, based solely on the information within each and every image.

So even though Guy comes down hard on most if not all modern sharpening tools and methods (high pass and ACR etc), he does put forward a few arguments that cannot be easily or at least entirely dismissed.

However Guy’s hyperbolic delivery, sprinkled with snippets of truth hidden behind a well developed hard edged sales patter, that plays heavily towards his strong points while hiding any weaknesses, and that warns us – whatever you do and whatever anyone else could do or tell you to do, is always going to be so much less than what you could ever hope to achieve if you pay for Guy’s help, because without his help, you are bound to be wrong, as only he has the key to the one true answer, is bound to put a lot of people off him and generate cries of ‘snake oil’ etc, but to dismiss everything he says outright just because he has decided to deliver his ‘solution’ in a way that seeks to denigrate every other method and tool, might be as I said earlier, an act of throwing out the baby with the bathwater.

So even though I think that overall, Guy is probably more wrong than he is right, there are still some areas where it does seem as though he is right, or at least very close to it.

Dave
Title: Re: PK Sharpener Question
Post by: Schewe on June 24, 2013, 06:08:52 PM
So even though Guy comes down hard on most if not all modern sharpening tools and methods (high pass and ACR etc), he does put forward a few arguments that cannot be easily or at least entirely dismissed.

Ever hear of Bruce Fraser's Thoughts on a Sharpening Workflow (http://www.creativepro.com/article/out-of-gamut-thoughts-on-a-sharpening-workflow)? Written about the time we finished PhotoKit Sharpener...in it Bruce advocates a capture, creative and output sharpening 3 pass approach. Which is exactly what Camera Raw and Lightroom were designed for. It addresses most if not all of Guys points (and predates them since Bruce 1st advocated multi-pass sharpening in his Real World Photoshop 3 book in 1996).

You can already apply global sharpening in ACR/LR and modulate the sharpening in the local controls...you can paint out sharpening or paint it in stronger locally. Yes, it requires some hand work...a few seconds to click on the Adjustment Brush and a few seconds to paint some strokes...Capture sharpening WAS designed to be evaluated on screen at 100%.

As far as output sharpening, Lightroom (and ACR) have that built in. The logic and routines were licensed by Adobe from PG for ACR/LR and no, you CAN'T properly sharpen for output sharpening on screen...that's why LR doesn't even let you see the results. That's on purpose...

The only point that Guy is somewhat right about is that the 5 sliders for sharpening (I count luminance noise reduction the 5th slider) isn't intuitive and needs to be learned. I've tried to teach people what the adjustments do and how to use them...Guy doesn't even bother–largely because I suspect he doesn't really understand them.

Can you do more exotic sharpening in Photoshop using a variety of masks and selections? You bet...but creating an edge mask is about a 15 step operation in Photoshop where in ACR/LR it's a wang bar fully adjustable between zero and 100. Hum, can you duplicate it in Photoshop? You bet...is it better in Photoshop? That's debatable. Are there 3rd party tools that extend even further than Photoshop? You bet...some have been mentioned here in this thread (but not mentioned by Guy of course).

So, yes, it takes some time and effort to learn how to use ACR/LR sharpening. Course, Guy isn't much of a help there. He just denigrates the tools and wants to sell you actions (which ironically depend on some of the same tools he denigrates).

Come on Dave, you aren't really drinking Guy's Kool-Aid are ya?
Title: Re: PK Sharpener Question
Post by: bwana on June 24, 2013, 09:50:53 PM


You can already apply global sharpening in ACR/LR and modulate the sharpening in the local controls...you can paint out sharpening or paint it in stronger locally. ...

The only point that Guy is somewhat right about is that the 5 sliders for sharpening (I count luminance noise reduction the 5th slider) isn't intuitive and needs to be learned. I've tried to teach people what the adjustments do and how to use them...

So, yes, it takes some time and effort to learn how to use ACR/LR sharpening. ...

I sometimes have trouble getting the creative sharpening I want to be what is printed. I set my view to 30%-50% which on my 100 dpi monitor should mimic 300-200 dpi printed output. And white halos are a pain as well...way back in the beginning I thought they were a little....cool. ??? but now they are splinters that i have to pluck out using "painted in sharpening" in only the areas of the photo that I want to draw the viewer to..

I do not have as much experience as others do playing with the cumulative effect of those sliders. As the algorithms behind them undoubtedly changed since Bruce wrote his books, I would welcome a comparative treatment of the same photograph using these two different workflows (PS based as illustrated by Guy, LR based as advocated by Schewe). I would even pay to watch 'workflow olympics' where great post-process artists are given the same raw image and 10 minutes to make it 'great' in the eyes of an anonymous panel of judges (us). I think Guy's tutorials are good because they emphasize the graphic qualities he is trying to portray and bring out in a photo. There is discussion about the form of an image, the tonal gradation, the color cast, the shadow noise. Although he does come down hard on his wang bars, I think it's not the Adobe tech that he is slamming, but the fact that they are so easy to misuse. As I am sure I do, often by accident. Still, if there is a thoughtful, simple webcast on the use of LR to achieve the kind of purposeful enhancement of an image, please point me to it.
Title: Re: PK Sharpener Question
Post by: Schewe on June 24, 2013, 11:38:31 PM
I sometimes have trouble getting the creative sharpening I want to be what is printed. I set my view to 30%-50% which on my 100 dpi monitor should mimic 300-200 dpi printed output.

Uh, you can't evaluate the final sharpening on a computer display. Even if you zoom out to 50-25%, you are looking at a higher rez image at 1/3 to 1.4 the resolution if your display is 100 ppi. All you can do is do the proper capture sharpening add creative sharpening and the final output sharpening should not break the image.

Just so you know, I would have absolutely ZERO interest in engaging in a sharpening competition...I've written books and done video tutorials and I post here on LuLa and the Adobe forums. Sorry, but have neither the time nor inclination to engage in that sort of circus...and to he brutally honest, I've now seen two essentially worthless videos by Guy...I won't be watching another one.

Quote
Although he does come down hard on his wang bars, I think it's not the Adobe tech that he is slamming, but the fact that they are so easy to misuse.

Did you see the same videos I did? In essence, he said ACR and LR are crap. He slams Adobe, he slams the engineers, he slams everything including Photoshop. Oh, he talks pretty glowingly about Aperture...I wonder why?
Title: Re: PK Sharpener Question
Post by: texshooter on June 25, 2013, 01:40:46 AM

Just so you know, I would have absolutely ZERO interest in engaging in a sharpening competition...

You mean even with a man who Photography Monthly says:

He is a legend in the world of digital imaging, workflow and manipulation.
His opinions set the agenda for manufacturers worldwide
As a leading authority, he is regularly retained by clients such as Adobe, Apple and Wacom
At the age of 19 he was the sole operator of the earliest digital scanner.
What he doesn't know about Photoshop is not worth knowing.

And you say you never heard of the man? Do you live under a rock?  ;)
Title: Re: PK Sharpener Question
Post by: Schewe on June 25, 2013, 01:54:53 AM
You mean even with a man who Photography Monthly says:

What's Photography Monthly? Sorry, never heard of it...maybe I do live under a rock...(although I tend not to read photo magazines that features dogs on the cover–silly me).

Like I said, Guy is a legend in his own mind...
Title: Re: PK Sharpener Question
Post by: BartvanderWolf on June 25, 2013, 04:59:05 AM
Uh, you can't evaluate the final sharpening on a computer display. Even if you zoom out to 50-25%, you are looking at a higher rez image at 1/3 to 1.4 the resolution if your display is 100 ppi. All you can do is do the proper capture sharpening add creative sharpening and the final output sharpening should not break the image.

Hi Jeff,

While that's essentially true, it may escape some readers why that is so. The reasons are quite simple and, more importantly, one can learn through experience how to deal with them.

Proper Capture sharpening is something that has not been understood well by many, for a long time, and some still don't. All it's supposed to do is recover from (as much as feasible) the sharpness (resolution and contrast) losses incurred during the Capture process. Some are still using yesteryear's tools (because nothing better was available back then) with some added features to hide the shortcomings.

What many do not realize is that the Capture process losses can be accurately predicted and quantified because they are predictable physical processes. When we know what caused them (optics, diffraction, sampling), we can use modern techniques (like Deconvolution) to recover from them to a large degree. BTW, the optics not only hurt the original signal's resolution due to residual aberrations, but are also a major cause of contrast loss due to veiling glare (which is not really being addressed by the ancient tools).

Modern Capture sharpening tools are quite outdated in their design, and they look very much like USM sharpening tools with some extras for artifact suppression.

UnSharp Masking (USM) based tools are just that, yesteryear's tools. They mimic a process that was used with analog film, and turned it into a digital tool that produces the same kind of artifacts as there were in film, and then uses edge masking techniques to cover up most of those artifacts. That's ancient, and it's also what Guy Gowan seems to use, although he seems to focus more on the final output than on real Capture sharpening.

The image as displayed on screen, can help to look in detail whether the adjustments do or don't create artifacts, but it cannot give a good impression of the real effect on final output, mainly because the display resolution is too low. Of course, through experience one can develop a feeling of how things will ultimately work out in output. The experience part is often not mentioned by those who slam the usefulness of judging on display sharpening adjustments.

Creative sharpening is a term that inaccurately describes all of the actual processes at this stage, because from it's origin it's partly based on the same ancient USM sharpening techniques. Of course it usually has relatively little to do with sharpening, but more with local contrast adjustments, e.g. Clarity.

Modern implementations of this Creative stage of image manipulation can, thanks to modern Digital Signal Processing (DSP) techniques (e.g. Wavelets and other frequency domain based adjustments), indeed address the manipulation (amplification or reduction) of specific spatial frequency bands in specific areas of the image. But most of the Creative influence on the overall look of an image comes from Local Contrast adjustments, not real sharpening but the impression of sharpness caused by contrast. Contrast suggests subject matter surface detail will be brought out by harsh lighting.

To get some idea about how the result will look in final output, one can very roughly approximate it by zooming out to a true output size on screen representation. The finer detail adjustments cannot be accurately judged on screen though, because the display resolution is too low, and the quick down-sampling not accurate enough. Through experience though, one can develop a feeling for how things will work out in the final output.

Output sharpening is usually also hard to exactly jugde on display, again, because the display resolution is too low, and because a light emitting output device has a different characteristic compared to reflective printed output, and viewing conditions can have quite a different effect on both. Of course when output is generated for screen display, e.g. Web Publishing, it becomes easier to judge the final result for a given display type (although there are a lot of different display qualities available for which one can optimize).

Again, experience plays a large role here in judging how the on screen adjustments will translate to the actual output medium. So while the on screen displayed image is not an accurate preview, one can learn how to translate that preview to how things will actually look, and experience takes time to develop.

Cheers,
Bart
Title: Re: PK Sharpener Question
Post by: PhotoEcosse on June 25, 2013, 05:04:14 AM
What's Photography Monthly? Sorry, never heard of it...maybe I do live under a rock...(although I tend not to read photo magazines that features dogs on the cover–silly me).



Photography Monthly is one of the many photographic monthlies. This month (July) has a bee on the cover. Prettier than a dog.

I think there is a problem with photographic magazines nowadays - far too many of them and a general dropping in standard. It seems that every major publishing house has to have at least three photographic titles. Photography Monthly is one of Archant's.

I remember the halcyon days of the 1950s when there were only two popular photographic magazines in UK - Amateur Photographer (weekly) and Practical Photography (monthly).

But, imho, the main problem is the standard of the journalism. It would not surprise me in the least if the quotations cited above were supplied by the subject himself, rather than being properly researched.

This new-fangled internet thing has a lot to answer for.
Title: Re: PK Sharpener Question
Post by: digitaldog on June 25, 2013, 10:03:46 AM
And you say you never heard of the man? Do you live under a rock?  ;)

I must be under a rock too, never heard of the that guy Guy until this post. Or that magazine (although while I haven’t seen it, I like dogs on covers and on the bed <g>).

I've been 'involved' with imaging since Photoshop 1.0.7 shipped in 1990, how could I have missed Guy? I recall Kai from under that rock a long time ago.
Title: Re: PK Sharpener Question
Post by: Garnick on June 25, 2013, 10:33:46 AM
I must be under a rock too, never heard of the that guy Guy until this post. Or that magazine (although while I haven’t seen it, I like dogs on covers and on the bed <g>).

I've been 'involved' with imaging since Photoshop 1.0.7 shipped in 1990, how could I have missed Guy? I recall Kai from under that rock a long time ago.

Oh come on Andrew...you haven't heard of the "GUY"?  12am every night on GGN(the Guy Gowan Network).  Ya, a well known talk show.  Of course it's "GUY" who does all of the talking.  Catch it sometime, it's a great replacement for the Nighty Night pill.  Only problem is, ummmm...it sucks.
Title: Re: PK Sharpener Question
Post by: Dave (Isle of Skye) on June 25, 2013, 01:24:04 PM
Come on Dave, you aren't really drinking Guy's Kool-Aid are ya?

No Jeff, not at all - BTW we don't have Kool-Aid in the UK, or any understanding of the term 'drinking Kool-Aid', although from your use of it, I think I get your drift  :D

But no, I am not swallowing what Guy has said in the slightest, or his overly persuasive sales technique that seeks to hide snippets of truth below a veil of mystery and yet to be revealed magic. His solution may not be worth anything at all, but if nothing else, he has given me enough food for thought to now drag myself out of the idleness that I had fallen into, of not being more attentive to exactly what I am doing when sharpening an image.

Dave
Title: Re: PK Sharpener Question
Post by: Rajan Parrikar on June 25, 2013, 01:54:21 PM

Output sharpening is usually also hard to exactly jugde on display, again, because the display resolution is too low, and because a light emitting output device has a different characteristic compared to reflective printed output, and viewing conditions can have quite a different effect on both. Of course when output is generated for screen display, e.g. Web Publishing, it becomes easier to judge the final result for a given display type (although there are a lot of different display qualities available for which one can optimize).

Again, experience plays a large role here in judging how the on screen adjustments will translate to the actual output medium. So while the on screen displayed image is not an accurate preview, one can learn how to translate that preview to how things will actually look, and experience takes time to develop.

Cheers,
Bart

Bart,

Somewhat tangential but, I think, relevant - the era where photos will mostly be exhibited on hi-res digital panels is not far off.  While a paper print is held up (by some) as the gold standard today, once the price of large hi-res panels drops, the game will change.
Title: Re: PK Sharpener Question
Post by: BartvanderWolf on June 25, 2013, 02:36:39 PM
Bart,

Somewhat tangential but, I think, relevant - the era where photos will mostly be exhibited on hi-res digital panels is not far off.  While a paper print is held up (by some) as the gold standard today, once the price of large hi-res panels drops, the game will change.

Hi Rajan,

Indeed, and I suppose that already more images are viewed on (low) resolution displays than there are printed, certainly large format. So it should be relatively doable to judge the sharpening for Low or High resolution displays on a reasonably calibrated display (which would allow at least some idea of how it could look on all those mediocre displays). A bit of experience goes a long way for when high resolution displays become mainstream.

Cheers,
Bart
Title: Re: PK Sharpener Question
Post by: digitaldog on June 25, 2013, 03:27:09 PM
I assume you haven't seen the video I was referring to from the "Guy".

Watched the first 16 minutes and had to stop for a reality break. I didn't learn anything other than his opinions about how great film and his Crosfield scans were, how everything else is subpar. I'm OK with a tutorial having some opinions mixed in with some actual teaching. But literally, there was no information disseminated in all that time. I suspect even someone totally new to the subject would have gotten nothing out of that first 25% of what is going to end up being a very long video. I'll continue to watch it as I'm sure at some point, something has to be discussed on the subject that is information based.

I'm not a fan of fast food quickie tutorials but at least the author's cut to the chase and if there are opinions, it's a 10%/90% ratio. What I saw of Guy's video in 15 minutes was more like 95% opinion and 5% possible information and I think I'm being generous! When Jeff says an hour of his life wasted, I get the idea and thus stopped quarter way through. But I'll give the guy another 15 minutes.
Title: Re: PK Sharpener Question
Post by: bjanes on June 26, 2013, 05:36:38 PM
Note that in Camera Raw, the clipping calculations are done in 8 bit based on the output color space set in Workflow Options. Also note there are 3 potential clipping indicators; holding down the option/alt keys when adjusting certain sliders, the on screen red for highlights and blue for shadows and the flashing triangle indicators on the histogram. Of the three perhaps the most accurate are the option/alt when moving a slider and the red/blue on screen indicator.

So, evaluating the differences between PV 2010 and 2012 in terms of clipping indicators being in 8 bit, it wouldn't surprise me that PV 2012 can (and does) get at more highlight texture detail that is not really clipped while PV 2010 shows the data as clipped.

When talking about "recovery", I think a lot of people get confused between recovery vs compression. PV 2012 does a lot of extreme highlight compression to mitigate clipping. Some people don't like that and you can work around that by using curves. When I think of recovery I think of the old Recovery algorithm in PV 2010. PV 2012 is NOT doing that sort of recovery...and PV 2012 doesn't suffer from the same color contamination that PV 2010 suffered from.

PV 2012 was originally designed for use in floating point HDR images...(see the Local Laplacian Filters article). It was adapted to work on non-HDR image in ACR/LR by the engineers and believe me, when I read the SIGGRAPH paper, my eyes rolled back in my head. I don't understand that stuff and never will.

But, I do know how to tell really smart people from not so smart people. I know Thomas and Eric pretty well and I've met Sylvain Paris (one of the authors of the paper) and they are really, really smart. I don't like the way Guy accuses Adobe of arrogance and denigrates the work of these guys...neither Thomas nor Eric are arrogant. OK, Mark Hamburg (the guy that started Lightroom and the second engineer to work on Photoshop) is a bit arrogant...but the engineers do this stuff to get the absolute best they can out of raw captures. They are not predisposed to back off on the raw processing and simply fix it in Photoshop.

I don't want to get involved in the discussion of Guy's sharpening workflow other than to state that he does not seem to know LR or ACR and his criticism of Adobe, Thomas, and Eric is misguided. However, he does point out valid differences in clipping indicators between PV2010 and PV2012. I will use LR5 to demonstrate these differences with a shot of a Stouffer wedge in which the green channels are blown in the raw file as shown by the Rawdigger histogram and overexposure indicator. Exposure was at 5000K on a lightbox. WB set to auto gave neutral results and a red multiplier of 1.973 and a blue multiplier of 1.555 so that the red and blue channels would also be clipped with white balance.

Here is the histogram of the file as shown by Rawdigger.
(http://bjanes.smugmug.com/Photography/LR-Clipping/i-z47wSsJ/0/O/Stouf_0008-Sel-3089-2229-3179x349.png)

And the Rawdigger clipping indicator.
(http://bjanes.smugmug.com/Photography/LR-Clipping/i-dhpWcNv/0/O/Stouf_0008-20130626-135942-RawDigger-ScreenShot.png)

The baseline offset for the D800e is +0.35 EV, so a negative exposure of -0.35 must be used with LR/ACR. Using LR with PV2010 and a linear tone curve shows the clipped channels.

Clipping indicator with PV2010 shows clipping similar to that shown with Rawdigger:
(http://bjanes.smugmug.com/Photography/LR-Clipping/i-KQJBkpS/0/X2/Clip1_08_PV2010-X2.png)

Alt exposure slider method with PV2010:
(http://bjanes.smugmug.com/Photography/LR-Clipping/i-TQKhqZW/0/O/Clip2_08_PV2010.png)

The PV2012 clipping indicator shows no clipping.
(http://bjanes.smugmug.com/Photography/LR-Clipping/i-T2jPgn2/0/O/Clip1_08_PV2012.png)

The Alt Exposure method with PV2012 also shows no clipping.
(http://bjanes.smugmug.com/Photography/LR-Clipping/i-5B63PBZ/0/O/Clip2_08_PV2012.png)

The conclusion is that PV2010 does give a more accurate indication of clipping.

Bill
Title: Re: PK Sharpener Question
Post by: digitaldog on June 26, 2013, 05:46:32 PM
I'm a bit confused Bill.

RD shows clipping, I get that. But then PV2012 shows none so is this clipping 'eliminated' by rebuilding that channel from the other two (an old 'trick' that was done in the past but perhaps differently with the new process)?
Title: Re: PK Sharpener Question
Post by: bjanes on June 26, 2013, 06:35:44 PM
I'm a bit confused Bill.

RD shows clipping, I get that. But then PV2012 shows none so is this clipping 'eliminated' by rebuilding that channel from the other two (an old 'trick' that was done in the past but perhaps differently with the new process)?

Andrew,

That is my take on the findings: PV2012 has applied an adaptive correction of the highlight clipping. The maximal pixel value with PV2012 is 253 but the upper tones are compressed. With PV2010 the first two steps are clipped to 255 and the third shows a color shift as shown. The PV2010 rendering is on the top.

Bill
Title: Re: PK Sharpener Question
Post by: digitaldog on June 26, 2013, 06:39:37 PM
That is my take on the findings: PV2012 has applied an adaptive correction of the highlight clipping. The maximal pixel value with PV2012 is 253 but the upper tones are compressed. With PV2010 the first two steps are clipped to 255 and the third shows a color shift as shown. The PV2010 rendering is on the top.

OK so it's rebuilding data in some respect and if so, it's accurate (the net results are, no clipping).

On the other hand, it's not accurate in terms of the actual data prior to rebuilding depending on how you want to look at it. IOW, PV2013 shows no clipping because it's going to produce no clipping. Sound about right?
Title: Re: PK Sharpener Question
Post by: bjanes on June 26, 2013, 06:49:36 PM
OK so it's rebuilding data in some respect and if so, it's accurate (the net results are, no clipping).

On the other hand, it's not accurate in terms of the actual data prior to rebuilding depending on how you want to look at it. IOW, PV2013 shows no clipping because it's going to produce no clipping. Sound about right?

Andrew,

Does LR5 use PV2012 or PV2013? The current process is identified as PV2012 in the LR display. In any event, the histogram shows the values in the rendered file, but does not indicate clipping in the raw file. This could cause problems when one is judging ETTR exposures.

Bill
Title: Re: PK Sharpener Question
Post by: digitaldog on June 26, 2013, 06:55:20 PM
Does LR5 use PV2012 or PV2013? The current process is identified as PV2012 in the LR display.

Sorry, typo on my part. There is no PV2013 (I'm referring to PV2012).
Title: Re: PK Sharpener Question
Post by: jrsforums on June 26, 2013, 07:03:41 PM
Looks like some form of auto-recovery to me....whatever you call it.

...oh...but the "expert" said this did not exist in PV2012....hmmm???
Title: Re: PK Sharpener Question
Post by: Schewe on June 26, 2013, 07:06:40 PM
In any event, the histogram shows the values in the rendered file, but does not indicate clipping in the raw file.

The histogram in ACR has always been the output refereed data, not the raw data. In Lightroom the histogram is Melissa RGB (ProPhoto RGB, sRGB tone curve–so pretty much output referred) or whatever RGB profile is set for soft proofing which is obviously output referred.

So, the question is, when RawDigger is showing that the raw data is clipped, what is PV 2012 doing with it to eliminate the clipping in the output referred data? Is it "recovery" as stated by Guy? Well, PV 2012 is NOT doing "recovery" the way recovery was done in PV 2010. I can guarantee that! So, exactly what is PV 2012 doing? I have a sneaky suspicion but I would defer to Eric Chan if he feels he can describe what's actually happening. When I describe PV 2012 as image adaptive and auto-ranging, that characterization was vetted by Eric. But understanding EXACTLY what is happening and what algorithms are being employed would require more imaging science than what I have. If you can read the Magic or Local Laplacian Filters? (http://blogs.adobe.com/lightroomjournal/2012/02/magic-or-local-laplacian-filters.html) and understand it, then I think you'll be closer to understanding what PV 2012 is actually doing. But PV2012 handling of tone mapping is NOT the same as PV2010's recovery...which is a very good thing in my book.
Title: Re: PK Sharpener Question
Post by: jrsforums on June 26, 2013, 07:19:14 PM
The histogram in ACR has always been the output refereed data, not the raw data. In Lightroom the histogram is Melissa RGB (ProPhoto RGB, sRGB tone curve–so pretty much output referred) or whatever RGB profile is set for soft proofing which is obviously output referred.

So, the question is, when RawDigger is showing that the raw data is clipped, what is PV 2012 doing with it to eliminate the clipping in the output referred data? Is it "recovery" as stated by Guy? Well, PV 2012 is NOT doing "recovery" the way recovery was done in PV 2010. I can guarantee that! So, exactly what is PV 2012 doing? I have a sneaky suspicion but I would defer to Eric Chan if he feels he can describe what's actually happening. When I describe PV 2012 as image adaptive and auto-ranging, that characterization was vetted by Eric. But understanding EXACTLY what is happening and what algorithms are being employed would require more imaging science than what I have. If you can read the Magic or Local Laplacian Filters? (http://blogs.adobe.com/lightroomjournal/2012/02/magic-or-local-laplacian-filters.html) and understand it, then I think you'll be closer to understanding what PV 2012 is actually doing. But PV2012 handling of tone mapping is NOT the same as PV2010's recovery...which is a very good thing in my book.

Jeff....who cares if it is the exact same recovery as PV2010.  I think everyone knows that Eric changed the algorithms (for the better).

Whatever the math....IS THIS RECOVERY or not?

Be a man.
Title: Re: PK Sharpener Question
Post by: digitaldog on June 26, 2013, 07:27:02 PM
Jeff....who cares if it is the exact same recovery as PV2010.  I think everyone knows that Eric changed the algorithms (for the better).
Whatever the math....IS THIS RECOVERY or not?

Consequently who care's what you call it? The clipping isn't there. The software doesn't show it's clipped and you don't get clipping. Seems accurate (accurate enough) to me.
Title: Re: PK Sharpener Question
Post by: jrsforums on June 26, 2013, 07:34:45 PM
Consequently who care's what you call it? The clipping isn't there. The software doesn't show it's clipped and you don't get clipping. Seems accurate (accurate enough) to me.

Hi, Andrew...

The point I was making is that auto-recovery is being done, which we were told was not (even though anyone who tested would know it). 

I agree that this recovery is great for most people....and in most cases....and protects them from "oh shucks" over exposure.  However, it will result in probable changes to color and texture and the ability to do further exposure reduction.  It doesn't take much testing to show how poorer the recovered areas are vs the same area in a properly exposed (non-recovered) image.
Title: Re: PK Sharpener Question
Post by: bjanes on June 26, 2013, 08:06:02 PM
Hi, Andrew...

The point I was making is that auto-recovery is being done, which we were told was not (even though anyone who tested would know it). 

I agree that this recovery is great for most people....and in most cases....and protects them from "oh shucks" over exposure.  However, it will result in probable changes to color and texture and the ability to do further exposure reduction.  It doesn't take much testing to show how poorer the recovered areas are vs the same area in a properly exposed (non-recovered) image.

The remapping of highlights that are blown in the raw file is definitely improved with PV2012. The highlights can be placed below 255 and color shifts are less likely with PV2012. However, this improved rendering can mask overexposure resulting from excessive ETTR and it would be helpful to have a raw histogram such as is available in Rawtherapee.

Bill
Title: Re: PK Sharpener Question
Post by: Schewe on June 26, 2013, 11:10:36 PM
The remapping of highlights that are blown in the raw file is definitely improved with PV2012.

Thanks for using a better term–remapping–because that's what I think is happening. It's obviously not "recovery" related to PV 2010. That's clear...and Guy, when he did the demo with the girl and violin chose to prove his point using PV 2010, not PV 2012. The result would have been considerably different if he had compared PV 2012 to Aperture.

With regards to ACR/LR's histogram, I think the argument for providing a scene referred raw histogram is only useful for image analysis purposes, not actual raw image processing. The output referred histogram is what's important for raw image optimized processing. For analysis purposes, RawDigger provides a useful set of tools which I applaud. But I wonder how useful a redesigned ACR/LR histogram would actually help image processing. I rarely pay much attention to the histogram when adjusting raw images–there is no such thing as a perfect histogram. It's simply a tool to evaluate your image. What's really the most important aspect is what does the image look like and what do you need to do to adjust it?

As to what EXACTLY happens with PV 2012 and clipped highlights, I've pinged Eric to see if he has an interest in explaining...but I got an auto-reply that he's on the road for a while. So, if/when he answers, it'll be down the road. As I said, I really don't understand the math behind PV 2012 and will defer to Eric...
Title: Re: PK Sharpener Question
Post by: jrsforums on June 27, 2013, 05:15:44 AM
Thanks for using a better term–remapping–because that's what I think is happening. It's obviously not "recovery" related to PV 2010. That's clear...and Guy, when he did the demo with the girl and violin chose to prove his point using PV 2010, not PV 2012. The result would have been considerably different if he had compared PV 2012 to Aperture.

With regards to ACR/LR's histogram, I think the argument for providing a scene referred raw histogram is only useful for image analysis purposes, not actual raw image processing. The output referred histogram is what's important for raw image optimized processing. For analysis purposes, RawDigger provides a useful set of tools which I applaud. But I wonder how useful a redesigned ACR/LR histogram would actually help image processing. I rarely pay much attention to the histogram when adjusting raw images–there is no such thing as a perfect histogram. It's simply a tool to evaluate your image. What's really the most important aspect is what does the image look like and what do you need to do to adjust it?

As to what EXACTLY happens with PV 2012 and clipped highlights, I've pinged Eric to see if he has an interest in explaining...but I got an auto-reply that he's on the road for a while. So, if/when he answers, it'll be down the road. As I said, I really don't understand the math behind PV 2012 and will defer to Eric...

The raw histogram is important if you want to know where your camera clips, which is important if you want to optimize your exposures.

FYI...from EC on 1/30/2012:

Highlight recovery is always enabled in PV 2012.  Combined with the highlight shoulder in PV 2012, this means that areas that would've shown as blown in 2010 may actually show as not clipped in 2012.  (Also, 2012's HL recovery is improved over 2010, for better detail extraction.)  This is the reason for the HL clip warning differences between 2010 and 2012.
Title: Re: PK Sharpener Question
Post by: BartvanderWolf on June 27, 2013, 06:06:35 AM
In any event, the histogram shows the values in the rendered file, but does not indicate clipping in the raw file. This could cause problems when one is judging ETTR exposures.

Hi Bill,

Although the thread's topic originally was more about sharpening before it turned into Guy bashing, you step-wedge images show the issues with tonecurve rendering in PV2012 nicely. The fact that highlights that are clipped in Raw do not show that in PV2012. In fact, it does an automatic highlight recovery and, IMHO more importantly, a default highlight compression. That latter fact is exactly what Guy Gowan was harping on about. 

As we can see in the attached chart I made from your Stouffer stepwedge conversions, and compare the PV2010 and PV2012 with the original step-wedge data, it is clear that the default PV2012 conversion suffers from significant upper midtone and highlight compression. That would indeed be detrimental for bride's dress and white cloud image content. The PV2010 conversion is much closer to how the original data (the blue line in my chart) would look in a straight conversion.

Of course Guy Gowan doesn't mention that the Highlights and Whites controls in PV2012 can help to restore highlight tonality, because that doesn't suit his agenda, but he does have a point that one would need to work the highlights in PV2012 conversion much more than usual, and similarly the shadows in a PV2010 conversion (which is what he advocates).

All this demonstrates that there is a bit of truth in all positions that are defended and that PV2012 can create a good image, with recovered highlights, but one really needs to work the PV2012 files very differently. One should e.g. not apply an simple S-curve or Clarity to a regular PV2012 conversion to boost overall contrast, if you want to keep some life in the highlight rendering. Work the highlights if you want the images to sparkle, and apply a curve adjustment if necessary.

Cheers,
Bart
Title: Re: PK Sharpener Question
Post by: bjanes on June 27, 2013, 07:37:03 AM
Thanks for using a better term–remapping–because that's what I think is happening. It's obviously not "recovery" related to PV 2010. That's clear...and Guy, when he did the demo with the girl and violin chose to prove his point using PV 2010, not PV 2012. The result would have been considerably different if he had compared PV 2012 to Aperture.
One can use the term recovery in a specific or generic sense. If one uses the term recovery to indicate the algorithms used in PV2010, then the remapping that PV2012 does is different. George Jardine has some excellent examples with back lit scenes in his LR4 develop tutorial where he was able to get considerably better results with PV2012. Perhaps Guy could learn something from George's tutorial.

With regards to ACR/LR's histogram, I think the argument for providing a scene referred raw histogram is only useful for image analysis purposes, not actual raw image processing. The output referred histogram is what's important for raw image optimized processing. For analysis purposes, RawDigger provides a useful set of tools which I applaud. But I wonder how useful a redesigned ACR/LR histogram would actually help image processing.
I agree that the histogram should show the distribution of levels in the rendered image when one is actually editing an image and am not suggesting that the behavior of the histogram should be changed, but it would be nice to have a switch in LR/ACR for use in image analysis such as is available in Rawdigger. This would avoid unnecessary trips to Rawdigger when one needs to have an indication of clipping in the raw file.

Bill
Title: Re: PK Sharpener Question
Post by: jrsforums on June 27, 2013, 08:11:09 AM
George Jardine also has a new tutorial "Image Correction Master Class". 

Does a great job showing how to manage tone and contast corrections....highlights being one of the ey areas.
Title: Re: PK Sharpener Question
Post by: BartvanderWolf on June 27, 2013, 09:00:08 AM
With regards to ACR/LR's histogram, I think the argument for providing a scene referred raw histogram is only useful for image analysis purposes, not actual raw image processing.

Hi Jeff,

I do not agree, but that may also have to do with how one processes one's files. It is because LR/ACR in PV2012 doesn't allow control over the Raw Whitepoint selection with the Exposure control any longer, but the Whites control might have some. It depends on how it is implemented under the hood. A Raw converter like RawTherapee does give the user direct control over the Raw Whitepoint, and it offers a Raw histogram, both of which together with clipping indicators to allow to make an optimal conversion.

Attached are 2 crops, one with Lightroom PV2012 (with Exposure -0.50 to get closer to the default RawTherapee average brightness),
and one with RawTherapee (with Raw Whitepoint to 0.80 to pull slightly more of the specular highlights into showing detail).

Besides the significantly more overall contrasty rendering by Lightroom, the huge difference in highlight detail is obvious. Also obvious is that both renderings are only basic conversions with lots of potential for tweaking, but this is the virtually straight out of the box rendering difference.

Cheers,
Bart

P.S. I've added a Capture One Pro conversion, coming in with also more detailed highlights which, a bit like RawTherapee, requires little work to get where they should be.
Title: Re: PK Sharpener Question
Post by: digitaldog on June 27, 2013, 09:37:19 AM
The raw histogram is important if you want to know where your camera clips, which is important if you want to optimize your exposures.

Which is why such a raw histogram needs to be on the cameras. Then one must account for exposure + development just like the old analog days, and different people will use different raw processors (the developing part). In that case, one would examine PV2012 and have a specific idea of how their development and their exposure work together.
Title: Re: PK Sharpener Question
Post by: opgr on June 27, 2013, 11:11:15 AM
I'm not sure that a RAW data histogram is specifically useful for the purposes of highlight clipping. The blinking highlight overlay we have discussed in the past is much more useful in that respect as it also shows how much of the data is affected perceptually. But yes, that overlay should be based on the rawdata.

However, I would like to make a case for being able to adjust the scale of the x-axis in the converter, because that I do find a tremendous help when making specific adjustments to dynamic range.

The attached images show an example.
- The first image shows the histogram in F-stops (incidentally in this case also the true RAW data). Because F-stops spread the dark tones and compress the highlights, I can easily judge the integrity of the darktones and at the same time adjust the level of absolute black with more ease and precision.
(Note that the RAW data without multipliers is not particularly comprehensive, even if it would only show the brightnesslevels).

- The second image shows the histogram in linear space,
This obviously does the exact opposite of the F-stops scale, and therefore allows me to check the integrity of the highlights and adjust the clipping level accordingly. It would also immediately show the parts that would be affected by highlight recovery algorithms.

- The third image is the final histogram in perceptual space,
Whatever I want to do next, I am certain that the dynamic range is fully utilized and the data in perceptual space is fully optimized because it spreads across the entire width of the histogram.
If I now want to apply local contrast enhancement, at least I can immediately judge with all certainty that I have exhausted the other possibilities of contrast optimization.

Title: Re: PK Sharpener Question
Post by: BartvanderWolf on June 27, 2013, 11:32:33 AM
Which is why such a raw histogram needs to be on the cameras.

Hi Andrew,

I think we all agree about that. But since we don't have that, we need to bracket and it would be useful if the Rawconverter would allow us to (without prior inspection by RawDigger) directly pick the best exposure based on actual Raw exposure, and tweak its rendering.

Cheers,
Bart
Title: Re: PK Sharpener Question
Post by: Schewe on June 27, 2013, 02:59:42 PM
Besides the significantly more overall contrasty rendering by Lightroom, the huge difference in highlight detail is obvious. Also obvious is that both renderings are only basic conversions with lots of potential for tweaking, but this is the virtually straight out of the box rendering difference.

Ironically, I prefer the Lightroom rendering (having recently shot a lot of waves and water on a vacation to Hawaii). Also, pulling the Whites slider down would allow you to tune the brightness of the whites considerably...

BTW, I really don't care about the "virtually straight out of the box rendering difference" comparisons of any raw converters...what I care about is the ability of a raw converter to optimize the image. When I use LR or C1, I tend to touch all the controls that are needed to get the image the way I want it so "out of the box" is pretty meaningless for me.
Title: Re: PK Sharpener Question
Post by: bjanes on June 27, 2013, 03:39:42 PM
Hi Bill,

Although the thread's topic originally was more about sharpening before it turned into Guy bashing, you step-wedge images show the issues with tonecurve rendering in PV2012 nicely. The fact that highlights that are clipped in Raw do not show that in PV2012. In fact, it does an automatic highlight recovery and, IMHO more importantly, a default highlight compression. That latter fact is exactly what Guy Gowan was harping on about. 

As we can see in the attached chart I made from your Stouffer stepwedge conversions, and compare the PV2010 and PV2012 with the original step-wedge data, it is clear that the default PV2012 conversion suffers from significant upper midtone and highlight compression. That would indeed be detrimental for bride's dress and white cloud image content. The PV2010 conversion is much closer to how the original data (the blue line in my chart) would look in a straight conversion.

Of course Guy Gowan doesn't mention that the Highlights and Whites controls in PV2012 can help to restore highlight tonality, because that doesn't suit his agenda, but he does have a point that one would need to work the highlights in PV2012 conversion much more than usual, and similarly the shadows in a PV2010 conversion (which is what he advocates).

All this demonstrates that there is a bit of truth in all positions that are defended and that PV2012 can create a good image, with recovered highlights, but one really needs to work the PV2012 files very differently. One should e.g. not apply an simple S-curve or Clarity to a regular PV2012 conversion to boost overall contrast, if you want to keep some life in the highlight rendering. Work the highlights if you want the images to sparkle, and apply a curve adjustment if necessary.

Bart,

Thanks for taking the trouble to plot out the values for the raw file and various renderings. To investigate these differences in another manner, I selected a wedge exposed just short of clipping as shown by Rawdigger.
(http://bjanes.smugmug.com/Photography/LR-Clipping/i-T62smd2/0/O/Stouf_0001-Sel-1099-2269-5149x309.png)

I then rendered it in PV2012 in sRGB with no exposure adjustment and the resulting plot was fairly linear except to the kink in the low pixel values where sRGB assumes a linear ramp. I then increased exposure by 1 and 2 EV using the exposure control of the raw converter with the results shown. Rather than clipping, the highlights are rolled off close to 255 but not clipped. I then selected another wedge exposed by the camera with +1 EV, and the results are very similar to those obtained with a +1 EV exposure increase made with the raw converter.

Rendering the overexposed file with PV2010 and a linear tone curve and the highlights in the 4 brightest steps were clipped to 255. The highlight differences in the brightest steps are hard to see in the graph, so I included them in tabular form below the legend. These results illustrate the image adaptive processing algorithms used in PV2012. With the overexposure, the brighter steps may appear blown on the screen with the PV2012 but are different and the normal appearance of the wedge can be restored with the tone mapping tools.

(http://bjanes.smugmug.com/Photography/LR-Clipping/i-XC3fBQF/1/O/Composite3.png)

Bill
Title: Re: PK Sharpener Question
Post by: BartvanderWolf on June 27, 2013, 06:41:41 PM
George Jardine also has a new tutorial "Image Correction Master Class". 

Does a great job showing how to manage tone and contast corrections....highlights being one of the key areas.

Hi John,

Yes, (almost) everybody comes to the same conclusion, i.e. that managing the compressed highlights is the main issue to address in PV2012 (just as is managing the shadows in PV2010). The complicating factor is that ETTR exposed images require much more correction than e.g. a 1 stop under-exposed shot that will have more default highlight contrast in a PC2012 conversion. Changing the overall exposure will require to adjust the Highlights and Whites as well.

Instructors like George Jardine and Martin Evening are generally considered to be reliable sources of information.

Cheers,
Bart
Title: Re: PK Sharpener Question
Post by: BartvanderWolf on June 28, 2013, 05:09:19 AM
Ironically, I prefer the Lightroom rendering (having recently shot a lot of waves and water on a vacation to Hawaii). Also, pulling the Whites slider down would allow you to tune the brightness of the whites considerably...

Hi Jeff,

It's not so much the brightness of the whites that becomes a challenge in PV2012, it's the highlight contrast in those tone-compressed whites. That doesn't have to be a problem as long as we can adjust the Raw conversion before it is demosaiced. Otherwise, after demosaicing, we will have lost some of the definition in the brighter tones already.

When you re-read the great article by Charles Cramer (http://www.luminous-landscape.com/techniques/tonal_adjustments_in_the_age_of_lightroom_4.shtml) you'll see that he needs to use a maximum setting of -100 Highlights Slider control to tame the highlight tonality. Also, the Clarity control compresses the highlights even further because it expands mostly the mid-tone contrast. Brightening the image with the Exposure slider also compresses the highlights. Working the highlights is a task of major importance in PV2012. Charles' summary is spot on.

When an image has significant highlight content, one may alteratively even prefer to process those in PV2010 (assuming the exposure was correct and not clipped), or blend 2 renderings in Photoshop from PV2010 (for the highlights) and PV2012 (for the mid-tones and highlights).

Quote
BTW, I really don't care about the "virtually straight out of the box rendering difference" comparisons of any raw converters...what I care about is the ability of a raw converter to optimize the image. When I use LR or C1, I tend to touch all the controls that are needed to get the image the way I want it so "out of the box" is pretty meaningless for me.

I agree that the straight out of the box rendering is only a starting point, however I'd rather start with a decent starting point. It's a bit like having to climb a steep hill, I'd rather start half way than at the bottom. Besides, some of the tonality may already be lost when the Raw conversion/demosaicing itself doesn't incorporate the taming of the highlights, parametric processing doesn't help with that. Doing it as post-Raw conversion is like climbing that hill with one leg.

Cheers,
Bart
Title: Raw Histogram in Raw Converter
Post by: Jack Hogan on June 28, 2013, 06:40:19 AM
Imho the need for a raw histogram in raw converters comes from the realization by IQ conscious photographers that as long as all desirable Raw image information/data is contained within 14-16 integer bits - making use of most of them - a perceptively 'good quality' image can be generated with full control of typical Raw Converter/Editor variables, by making a number of informed choices and compromises.  These choices and compromises can be quite different whether the desirable highlight in question is clipped or not, although both final images may at first appear similar to a naive observer.

So given that the objective of the IQ conscious photographer in the field is to ETTRv2 subject to his artistic constraints in order to ensure that s/he starts with all desirable information captured and at its best, the objective of the Raw Histogram/blinkies in the Raw converter is to confirm that that is indeed the case - and if it's not to give him/her the information s/he needs in order to make his/her informed choices and compromises.

For instance if one knows that desirable highlights are irretrievably clipped in the raw data, one may not even try to reduce image values linearly (-EC) in order to attempt to give them more detail in a subsequent PP step.  Conversely, if they are not clipped in the Raw data but are apparently so in the finally rendered image, one may decide to apply -EC in the Raw Converter and compensate for it by adding brightness/contrast (local and otherwise) in other ways.

There are equivalent examples in the shadows, and I personally find myself tripping back and forth to RawDigger at the beginning of a conversion to check just this sort of thing out.  I would find it very useful to have some of its functionality built into current Raw conversion software.

Jack
Title: Re: PK Sharpener Question
Post by: Jack Hogan on June 28, 2013, 08:24:45 AM
When you re-read the great article by Charles Cramer (http://www.luminous-landscape.com/techniques/tonal_adjustments_in_the_age_of_lightroom_4.shtml)

A good article indeed.  It also shows how far ACR/LR's terminology has drifted from both a technical and practical frame of reference (e.g. 'Exposure' appears to control (mainly) midtones, non-linearly).

Jack
Title: Re: PK Sharpener Question
Post by: kirkt on June 30, 2013, 11:21:12 PM
You can construct a 32 bit per channel step wedge in PS, over an arbitrary range of exposures, save it as a floating point TIFF and open it directly in ACR to see what kind of range-adaptive and automagic adjustments are going on in PV2012 compared to PV2010.  Because your step wedge will be rendered in the ACR histogram as very thin spikes, add a little bit (Amount 5, Size 10) of film grain to soften the spikes into a more Gaussian-looking profile at each step.  I also make a 50% gray (i.e., brightness = 50%, 0.00 exposure in the 32bit color picker) bar across the entire image - this will give the 0 exposure a larger "hump" in the ACR histogram, so you have an idea of where your middle value is.  Try making a -4 to +4 step wedge in 0.5 exposure increments for starters.  Then open the resulting TIFF in ACR and try making adjustments to the tone sliders in PV2010 and PV2012 with the clipping indicators on to see how the histogram changes.  You can also see the way Recovery / Highlight, as well as Clarity, in PV2010 and 2012 changes across the histogram.  You can also change the output color space to see how that affects the histogram.

While PV2012 may give more pleasing results, the controls are not intuitive in terms of how tonal range is manipulated with each slider adjustment - for example, how deeply one slider's effect reaches into the adjacent tonal range values (it appears that the effects of each slider are transitioned into adjacent tonal ranges to a degree which will prevent artifact, but how far into the range is hard to appreciate).  Instead of adding a "raw" histogram to ACR (we can always see our raw data in Raw Digger) why not add a graphical representation of the tone(mapping) curve that is being applied in the auto-adaptive PV2012?  If there are auto-shoulder or auto-roll-off operations that are being applied to the raw data, then why not display that curve behind (superimposed on?) the histogram?  At least that kind of indicatrix, sort of like a film curve, will give the user more feedback on which area of the full tonal range the particular wang bar is operating and how that slider is mapping that tonal range.

The step wedge obviously has very well-defined, discontinuous areas of tone, so the effects of the sliders in each PV may not necessarily be the best representation of the perceived effect in a photograph - however, it is easier (for me) to get a sense of how tones are being [re]mapped with a contrived image like the step wedge.  I imagine that if one varies the range and extent of the various step wedges, one may also get a sense of the range-adaptive effects inherent in PV2012.  I have not bothered to go this far at this point.

Kirk
Title: Re: PK Sharpener Question
Post by: Temp on October 26, 2015, 03:47:44 PM
First off, my sincere apologies for bringing back a two-year old thread from the dead. Been considering making a post here for some time, and as I have been unable to get the thread out of my mind, here I am. No idea if the members who posted here are even still around, but I would just like to add my own perspective to a part of the discussion. I intend this post as a one-off and I have to stress I'm not looking to incite a big debate or make any enemies- but I'm here because I find some of the content in this thread a little objectionable.

What brought me to this thread in particular is searching "Guy Gowan" on Google - this topic is a prominent result. I first found it when I was looking up Guy a couple of years ago. I was considering joining his website having heard and seen good things, and decided to see what the word was on the web. By the time I had finished reading this thread I was wholly convinced that everything I knew about Guy was wrong, and that he was some sort of hack looking to get me hooked on some hokey presets and then leave me none the wiser.

This put me off joining for some time, but after much debate and second-guessing myself, I did sign up to Guy's site. I have been a member for a year and a half now, and I have learned tremendous amounts and would not take back a penny of my money. I think a lot in this thread is very misleading and somewhat slanderous, although perhaps for understandable reasons.

If there is one thing I absolutely concur with, it is that Guy's attitude in the FOCUS Webcasts is poor if not repulsive. Guy has quite the personality and is not the type to have a great awareness of how his attitudes affect perceptions. That said, in the end his attitude is immaterial to me, because it is not relevant to his expertise or teachings.

I can't pretend to be an expert, but if there is anything out there better than Guy's techniques, I haven't been able to find them. I've learned Guy's methodologies inside-out and from the ground-up, and they are extremely scientific, not to mention straightforward, repeatable, and logical. Learning Guy's approach to work was a huge breath of fresh air for me, because he dispels so many of the myths surrounding image manipulation today. If I may take a quote from elsewhere, this puts it better than I can:

Quote
[...]

Have been following Guy's techniques since 2006 (Sheesh, only realised it's almost a decade) when I first met Guy in Dublin. First bought his DVD's and then became a member of the first site.

When I first met Guy I was having an awful time trying to get to grips with Post Production and learning how to operate in PhotoShop (V7 back then). It was the first software package I had ever come across that I could not figure out how to work it myself. There seemed to be many people out there who would tell you how I should do things but many were people with about as much idea as myself but with bigger ego's. Then there were the "guru's" who would give you a bit of a demo but if you wanted more you had let the moths out of the wallet.
Wandering into one of Guy's seminars for me was so refreshing. This was the first person I had seen who was not repeating parrot fashion what everyone else was saying. He was teaching from a solid base of knowledge and using (gasp) LOGIC. None of the "This technique will work really well on the sample image, and will work for you if the third moon is rising in the house of Sagittarius" BS. I remember one thing very clearly, it was when someone asked about images being 300dpi. Nobody in the room knew why 300dpi became the gold standard (except Guy) and he then explained the reason and showed why it was bollocks.
The thing that impressed me most was that Guy would show his whole technique on a subject even in a free seminar. There was no high pressure sales talk. He did come across as quite opinionated, but with good reason. When I would have a chat with him he had time to listen and offer help, even though he was as bust as a Blue Arsed Fly, literally flying all over the place.
I happened to be at the birth of Webcasting too. That also happened in Dublin where Guy was booked to appear. However he was stuck in Amsterdam due to the Volcanic Ash. Rather than cancelling he arranged a Video Link and presented that way, with very big delays.
What has always impressed me with Guy is that even in free seminars he would show the full technique on a subject. There was no showing a bit then point to the DVD and saying the rest is in here. I sought out the DVD's to buy them and later became a member of the first site.

[...]

If you'll forgive the tone of that post, my experience is very similar. The first I saw of Guy was actually at a talk he gave at my local Photographic Club. I was only getting into photography at the time (hardly even knew what RAW was) so I did not understand half of what Guy said - but what was reassuring and impressive was that he showed, completely for free, his full techniques on a range of subjects, destroying conventional methods and leaving all the PS "experts" in the club with their jaws hanging open, speechless. A good while later, when I actually knew how to operate a camera and what a RAW file was, I too was having a terrible job getting into manipulating images and RAW workflow. The tools did not seem good or intuitive, and while there were a huge number of "experts" both online and off with a plethora of advice and techniques, nobody really seemed to have a good, objective approach. Having my memory of Guy at the club, I decided I should search him. My memory of his talk being faint, that was when I Googled his name, and then read this thread, which made me wonder if my memory of his talk was all wrong and I had just been taken in.

That was absolutely not the case - Guy's techniques are the best thing that ever happened to me.

Take a totally basic subject like contrast - in the world of photography people are taught to accept that contrast, be it in a "wang bar" or an S-Curve, is something that naturally distorts colour, and that is just the way it is and how it works. As Guy likes to point out, there is zero reason that this should be the case. Due to the fact that an S-Curve is fundamentally flawed and Adobe's algorithms were no better, in PS version 1 Guy came up with an alternative to the S-curve that is totally non-destructive to colour, and has taught it ever since. Not only is it good, but it is highly versatile, having the capacity to be mechanically refined for Portraits, Landscapes, High-Key and Low-Key images, and far more. Even in its most basic, unrefined form, it is still better than what is in software today, and Guy came up with it something around 25 years ago. That is hardly something you would get from someone who is "more wrong than they are right" or a "Ken Rockwell", as I was lead to believe when I read this thread years ago.

What has always impressed me the most is that there is just no nonsense in Guy's techniques. Despite being far ahead of conventional tools, Guy's contrast, colour, sharpening, retouching, you name it, is all incredibly simple and straightforward once you learn the theory behind it. Yet despite their beautiful logic and simplicity, there is not a soul at Adobe or any other software developer or PS user that I know of that has come up with the same technique or anything that parallells them. For this reason I have great respect for Guy. His techniques aren't some sort of magic trick or elitist complicated-for-the-sake-of-it type thing, they are basic, logical tools, which I see as what should be the standard in software, but isn't. It's not like you'll never again in your life have a problematic image, but never again having to worry about colour shifts in contrast (vastly expanding how much you can add) and being able to intuitively manipulate colour and sharpen images mechanically, among many other things, makes for a very fine start point.

I see people in this thread saying Guy bashes or does not support various tools or features because they do not fit his "agenda". Guy's agenda is getting good image quality in a scientific, repeatable fashion. One of the things that I appreciate the most is that he has no ulterior motives in his opinions on software. If a tool or feature is good, he will use it, and if it is bad, he will discard it and come up with a better solution. I have never seen Guy discard something just so he can be elitist or snobbish or be different for the sake of being different - he does it because the tools are sub-par and can be surpassed easily with his knowledge and skill.

I think perhaps the biggest misconception is that Guy is looking to sell or get people hooked on "presets". It is true that Guy's Process action is probably the biggest reason people sign up to the website - it is very good, and a much pirated entity (just like his DVDS). But if there is one thing I have heard Guy say over and over again with great disappointment, it is that he never intended the action to become a product. Guy says very often that he set out to teach people how to manipulate images properly and build their own tools (the Process action being a working prototype, a model for people to base theirs on) but the vast majority of people just want a button to click to make their lives easier, so the majority just join, download Guy's actions, and then never take the time to learn the theory or how to make them themselves. I am in a small minority of the membership that learned the whole lot - I have not used Guy's actions in a long time as I am able to build bespoke sets myself to suit my own needs, using Guy's theory.

I could go on and on, but I think I've said enough - this post is already far longer than I intended. I don't think I've even put my point of view as well as I'd like, but there's probably little point writing and rewriting. All I can say is, don't knock it 'til you've tried it. I can't say I expect anyone here to go rushing off and signing up to the website of a man they hate - but it just pains me to see this topic still showing high up on a Google search, and I thought I should at least add my perspective. I have to say I understand the frustration and anger of the members in this thread due to Guy's pompous attitude in the FOCUS Webcasts, but on the flip-side I think it's a bit unfair and damaging to Guy's business (which is a very legitimate and good one, despite what the free-to-view material would have you believe) that this topic is one of the things that shows up when you search his name, not to mention a bit of a disservice to people such as myself, as I was almost put off joining. I would be in a very poor position today without GG's theory.

Anyway, that's it from me. I hope this post does not seem coarse or insulting in any way - am not looking to have a go at anyone, but these are my honest experiences. All the best.
Title: Re: PK Sharpener Question
Post by: Manoli on October 26, 2015, 09:52:19 PM
First off, my sincere apologies ...

Good first post.
Long on rhetoric but short on substance.
Title: Re: PK Sharpener Question
Post by: Temp on October 27, 2015, 06:32:39 AM
Please be respectful - I know my writing isn't very good and that felt like a bit of a stab. It's difficult to convey my experiences on Guy's site without sharing the techniques themselves (the substance) but doing so on a public forum would be unfair to Guy as they are his own invention and he does make a living teaching them. Again, I'm (trying) to share my honest experiences, and I'm sorry if that seemed like a total rattle.

E: If it would be any better, I could privately share some of the basics with you. Basic contrast, basic colour, and basic sharpening are all relatively straightforward and it wouldn't be hard to give you the steps via PM.