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Jimbo57

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Sharpening
« on: October 28, 2015, 08:39:10 am »

Question for discussion.

Is the apparent unhealthy obsession of some forum contributors with "sharpening", an indication of:

(a) Fingerprints on lenses

(b) Poor focus

(c) Camera shake

(d) Atmospheric pollution

or what?

Apart from a routine need to apply a slight degree of sharpening to Raw files to compensate for deficiences in raw capture technology, what gives?
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Mark D Segal

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Re: Sharpening
« Reply #1 on: October 28, 2015, 09:15:48 am »

No, I don't think it's an indication of any of (a) to (d), though you are quite right that all of those factors influence "sharpness" well before we get to raw processing.

The discussion needs to be divided technically into at least two major considerations: (i) "edge sharpening" which is enhancement of contrast at fine edges between lighter and darker pixels to achieve what you say in your last sentence, or (ii) "deconvolution sharpening" which is an effort to "unwind" mistakes such as poor focus and camera shake. Some times people argue at cross-purposes about these technologies because they are failing to relate the technology to its bespoke purpose.

Apart from that, the discussions can depart from reality due to the practice of extreme "pixel-peeping", done to observe impacts that for all intents and purposes would be normally invisible on printed output, and hence operationally "unreal". This I would agree is obsessive, and in every walk, of life including this one, there are obsessive-compulsive people who are of course free to voice their observations.

But there is also a fair bit of healthy discussion about the relative PRACTICAL qualities of the various sharpening algorithms on the market, and that makes useful reading when it happens. So in the final analysis it is up to the readers to parse these threads and "focus" (pun intended) on what is useful to them.
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Mark D Segal (formerly MarkDS)
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D Fosse

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Re: Sharpening
« Reply #2 on: October 28, 2015, 10:50:11 am »

 :D

I don't mind reading these threads for whatever useful tricks might turn up. But when the graphs and spectral plots and nyquists and fast fourier transforms take over, I'm gone. I just don't have time, I have work to do. Where do all these graphs come from?

But it's great that people dig into this stuff, and this is as good a place as any. Someone has to do the dirty work, so the rest of us can skim... 8)
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stamper

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Re: Sharpening
« Reply #3 on: October 28, 2015, 11:35:20 am »

:D

I don't mind reading these threads for whatever useful tricks might turn up. But when the graphs and spectral plots and nyquists and fast fourier transforms take over, I'm gone. I just don't have time, I have work to do. Where do all these graphs come from?

But it's great that people dig into this stuff, and this is as good a place as any. Someone has to do the dirty work, so the rest of us can skim... 8)

Heartily agree!

rdonson

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Re: Sharpening
« Reply #4 on: October 28, 2015, 12:55:16 pm »

:D

I don't mind reading these threads for whatever useful tricks might turn up. But when the graphs and spectral plots and nyquists and fast fourier transforms take over, I'm gone. I just don't have time, I have work to do. Where do all these graphs come from?

But it's great that people dig into this stuff, and this is as good a place as any. Someone has to do the dirty work, so the rest of us can skim... 8)

You're singing to the choir!!!   ;D
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Ron

ErikKaffehr

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Re: Sharpening
« Reply #5 on: October 28, 2015, 03:22:51 pm »

Hi,

I would add:

f) obsession with pixel peeping.

I would state that the ideal state of pixels would be pretty fuzzy, but that does not bring us bragging rights, so we sharpen a bit to much at the pixel level, which is pretty irrelevant on both screen size images and prints, possibly ignoring detail that possibly has more relevance in any real picture.

So, he or she who is without sin may cast the first stone and the offenders may leave in peaceā€¦

Best regards
Erik

Question for discussion.

Is the apparent unhealthy obsession of some forum contributors with "sharpening", an indication of:

(a) Fingerprints on lenses

(b) Poor focus

(c) Camera shake

(d) Atmospheric pollution

or what?

Apart from a routine need to apply a slight degree of sharpening to Raw files to compensate for deficiences in raw capture technology, what gives?
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Tim Lookingbill

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Re: Sharpening
« Reply #6 on: October 28, 2015, 05:43:02 pm »

Though I would like a good and thorough outline with examples showing 100% crops of full size image vs the same crop for versions downsampled for the web. I don't know how many times I have to go back and forth adjusting sharpening on Raws to compensate downsampling in Photoshop on 6MP to 700 pixel on the long to get distant trees to look right in landscapes.

Sometimes just using ACR's default sharpening and letting "Sharpening for Glossy Paper-High" does a better job but as usual it varies according to scene and subject distance.
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Dale Villeponteaux

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Re: Sharpening
« Reply #7 on: October 28, 2015, 06:56:59 pm »

Has anyone adjusted their sharpening techniques because
of cameras with no optical low-pass filter?

Regards,
Dale
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David Sutton

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Re: Sharpening
« Reply #8 on: October 28, 2015, 09:44:42 pm »

Has anyone adjusted their sharpening techniques because
of cameras with no optical low-pass filter?

Regards,
Dale

Hard to know whether we change our techniques due to the camera or due to increasing age and experience.
Not an answer to your question, but since switching to Fuji X-Trans I've thrown my sharpening workflow out the window. The Fuji files can take a lot more sharpening without falling apart, but that of course doesn't make the result better.
I'm looking for a 2% improvement with each layer group in Photoshop, and that includes sharpening. What constitutes an improvement? That depends on the subject matter and output.
I seem to have become overly sensitive to haloing, so now I do minimal capture sharpening and then sharpen with Topaz Detail put through a luminosity mask. Looks nice and seems more gentle.
David

Edit: thinking of the original post, can anyone name any aspect of photography where a google search won't reveal an apparent unhealthy obsession lurking somewhere in the world?
« Last Edit: October 28, 2015, 09:53:41 pm by David Sutton »
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studio347

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Re: Sharpening
« Reply #9 on: October 29, 2015, 07:31:28 am »

I want to add a few points regarding sharpening~
The sharpness is very much related with the sharp quality of light itself in the picture. If the light in a image is sharp, the image can be sharper...
And The tendency to mimic the real human vision, is also related with the desire for the sharpness in photo images. Human vision is quite sharp when a person looks with concentration.
The desire to mimic the real vision or the concentration and the lighting quality in images are 2 things I have in mind when considering sharpness.

Also, there has been a long history of photography to make sharper image from the start. 8 by 10 and bigger films and the contact prints were the end point at the film period. With the digital, the quality of sharpness dropped quite at the start. It has improved for last 15 years, but not quite yet compared with real human vision and contact prints of big films. Sharpness is one quality some people have obsession. Naturally some people don't have it. The post-digital sharpening is a bit different approach even though closely related~
« Last Edit: October 29, 2015, 07:34:30 am by studio347 »
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Bart_van_der_Wolf

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Re: Sharpening
« Reply #10 on: October 29, 2015, 09:47:03 am »

I seem to have become overly sensitive to haloing, so now I do minimal capture sharpening and then sharpen with Topaz Detail put through a luminosity mask. Looks nice and seems more gentle.

I agree, haloing is unnatural and shows a lack of attention (disrespect for the viewer), the more so because it is almost totally avoidable. Topaz Detail does a stellar job of turning a bleh image into something (very) good looking.

Quote
Edit: thinking of the original post, can anyone name any aspect of photography where a google search won't reveal an apparent unhealthy obsession lurking somewhere in the world?

The OP failed to qualify 'obsessive'. Such broad sweeping dismissive statements are often founded in ignorance. Dissatisfaction about the results will lead to lots of discussions. Without some proper guidance that will not lead to much, which then may be erroneously interpreted as 'an obsession' to discus it.

One man's obsession is another one's attention for detail. Obsession for me begins when more effort makes no difference to the result. Proper(!) sharpening is poorly understood to begin with, and the standard tools are lacking in capability. That's why tools like FocusMagic and Topaz Detail have such a satisfied following, they make a world of difference.

Cheers,
Bart
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Mark D Segal

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Re: Sharpening
« Reply #11 on: October 29, 2015, 10:39:30 am »

Proper(!) sharpening is poorly understood to begin with, and the standard tools are lacking in capability. That's why tools like FocusMagic and Topaz Detail have such a satisfied following, they make a world of difference.

Cheers,
Bart

And by who is "sharpening poorly understood to begin with"? And what "standard tools are lacking in (what kind of) capability"? I find these statements kind of cavalier. You find Focus Magic and Topaz Detail satisfying - that's your observation for what you do, and so be it, but don't cast aspersions on other people who find other tools perfectly satisfactory for their requirements.
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Mark D Segal (formerly MarkDS)
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smthopr

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Re: Sharpening
« Reply #12 on: October 29, 2015, 12:15:43 pm »

Question for discussion.

Is the apparent unhealthy obsession of some forum contributors with "sharpening", an indication of:

(a) Fingerprints on lenses

(b) Poor focus

(c) Camera shake

(d) Atmospheric pollution

or what?

Apart from a routine need to apply a slight degree of sharpening to Raw files to compensate for deficiences in raw capture technology, what gives?

my 2 cents:

I sharpen every image.  But, not necessarily to make the image look more in focus or detailed.

I use only the "unsharp mask" control in photoshop.  But at widely different settings to achieve the results I'm after. I often duplicate my image layer and apply  the effects by painting them into regions of the image using layer masks.  For me, it's all about dramatic impact.  Often more of a contrast control than an attempt to make my images look more detailed. 

But I will say this in general.  Areas of high detail and also, areas of high contrast attract the eye, so it becomes part of the composition you are making. Not usually about "focus"
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ErikKaffehr

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Re: Sharpening
« Reply #13 on: October 29, 2015, 04:14:53 pm »

Hi,

Yes and no. What I have found is that it is nice to have images that look great when pixel peeping at actual pixels. On the other hand pixel peeping is a very unrealistic way of looking at images. So I can feel that it may be good to back down quite a bit on sharpening. Lightroom has a setting for "landscape sharpening" that was developed by Jeff Schewe, that may be a good starting point.

Human vision is dominated by medium to low frequency detail, so enhancing pixel level detail at the expense of low to medium frequency detail may be a less than optimal sharpening strategy. This video explains some things pretty well: https://www.youtube.com/watch?v=iBKDjLeNlsQ&ab_channel=FallenEmpireDPS

Best regards
Erik

Has anyone adjusted their sharpening techniques because
of cameras with no optical low-pass filter?

Regards,
Dale
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Bart_van_der_Wolf

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Re: Sharpening
« Reply #14 on: October 30, 2015, 10:55:16 am »

And by who is "sharpening poorly understood to begin with"?

Hi Mark,

I said "Proper(!) sharpening is poorly understood to begin with, and the standard tools are lacking in capability."

Lot's of misguided advice about sharpening is floating around on the internet, most of it are old insights based on pre-digital concepts, such as USM sharpening. One of the better references is Real World Image Sharpening, by Bruce Frazer and Jeff Schewe, but a large proportion of that is also about hiding the halo artifacts caused by using sub-par techniques such as the Sharpening tools in LR and Photoshop.

Anybody who doesn't know about the difference between (deconvolution) sharpening and (USM type) edge contrast boosting, will have a lot of latent quality in their images that they are not utilizing.

Quote
And what "standard tools are lacking in (what kind of) capability"? I find these statements kind of cavalier. You find Focus Magic and Topaz Detail satisfying - that's your observation for what you do, and so be it, but don't cast aspersions on other people who find other tools perfectly satisfactory for their requirements.

If you think that I'm the only one who is very pleased with the superior capabilities of these tools, then you are mistaken. Everybody in the field of Digital Signal Processing (DSP) knows that deconvolution is the proper way to restore resolution, instead of boosting edge contrast to fool our eyes. Real resolution can be restored, as was required for the early Hubble Space Telescope imagery which revealed a design flaw that caused blurred detail. A software deconvolution process, i.e. Richardson-Lucy deconvolution, restored a lot of the resolution that was inititially missing.

The implementation of deconvolution (Detail slider blends between USM-type and Deconvolution-type of sharpening) in e.g. Lightroom is rather poor compared to the alternatives mentioned. Artifacts and halos are mentioned often as negative side effects, and the edge masking is there for a very good reason, given the shortcomings. The Detail panel even starts with setting the Amount slider instead of the Radius slider, which is the wrong order of adjustment for Capture sharpening. It also doesn't use EXIF information (Apterture used, focus disctance, sensel pitch, ISO) that can be used to preset reasonable defaults.

By the way, Capture sharpening is a correction of purely hardware characterized blur that's inherent to the capture process. It requires different settings than for Creative 'sharpening', yet the same settings are used in the standard tools of LR and similar.

It's not the fault of individuals that the tools they are offered provide lower quality than the tools I mentioned. So if they are satisfied with the best their software has to offer, fine. But that doesn't mean that they cannot improve the quality of their images, if they care. They just need to use other tools, and they may like what they can achieve then, better than what they can do now. They can also ignore the improvement suggestions, fine with me.

I'm hesitating to demonstrate the benefits of better tools, because I might get labeled obsessive, or casting aspersions on other people. I certainly do not want to waste my and your time explaining if that is not appreciated.

Cheers,
Bart
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Mark D Segal

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Re: Sharpening
« Reply #15 on: October 30, 2015, 11:15:02 am »

I very much appreciate good technical explanation and technical demonstration that digs below the level of generalities. I also bear in mind the practical significance of such findings from  workflow and image evaluation perspectives. So sure, I'm keen to see more about the relative practical merits of breaking the LR workflow with sharpening tools that achieve visually superior results without using unreal levels of magnification or loupes.
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jrsforums

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Re: Sharpening
« Reply #16 on: October 30, 2015, 11:33:39 am »


I'm hesitating to demonstrate the benefits of better tools, because I might get labeled obsessive, or casting aspersions on other people. I certainly do not want to waste my and your time explaining if that is not appreciated.

Cheers,
Bart

I would like to hear more on this.  I am sure others would also.
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John

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Re: Sharpening
« Reply #17 on: October 30, 2015, 11:57:58 am »

<>

Anybody who doesn't know about the difference between (deconvolution) sharpening and (USM type) edge contrast boosting, will have a lot of latent quality in their images that they are not utilizing.

If you think that I'm the only one who is very pleased with the superior capabilities of these tools, then you are mistaken. Everybody in the field of Digital Signal Processing (DSP) knows that deconvolution is the proper way to restore resolution, instead of boosting edge contrast to fool our eyes. Real resolution can be restored, as was required for the early Hubble Space Telescope imagery which revealed a design flaw that caused blurred detail. A software deconvolution process, i.e. Richardson-Lucy deconvolution, restored a lot of the resolution that was inititially missing.

The implementation of deconvolution (Detail slider blends between USM-type and Deconvolution-type of sharpening) in e.g. Lightroom is rather poor compared to the alternatives mentioned. Artifacts and halos are mentioned often as negative side effects, and the edge masking is there for a very good reason, given the shortcomings. The Detail panel even starts with setting the Amount slider instead of the Radius slider, which is the wrong order of adjustment for Capture sharpening. It also doesn't use EXIF information (Apterture used, focus disctance, sensel pitch, ISO) that can be used to preset reasonable defaults.

By the way, Capture sharpening is a correction of purely hardware characterized blur that's inherent to the capture process. It requires different settings than for Creative 'sharpening', yet the same settings are used in the standard tools of LR and similar.

Well said, Bart.

I routinely and obsessively use the L-R de-convolution sharpening option in RawTherapee (RT) - even though I've read somewhere that it is a (Gaussian?) approximation to the Real Thing.

As an aside, the thing with RT is it only gives one shot at Unsharp Mask - whereas in other editors it can be repeated with various settings to increase one's image acutance. This to me is a slight drawback.
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Bart_van_der_Wolf

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Re: Sharpening
« Reply #18 on: October 30, 2015, 12:44:18 pm »

Well said, Bart.

I routinely and obsessively use the L-R de-convolution sharpening option in RawTherapee (RT) - even though I've read somewhere that it is a (Gaussian?) approximation to the Real Thing.

Ted, the RawTherapee RL deconvolution implementation is quite good, but it is indeed rather basic (which makes it easy to use though). It also works on e.g. imported TIFFs, not only on converted Raws.

Quote
As an aside, the thing with RT is it only gives one shot at Unsharp Mask - whereas in other editors it can be repeated with various settings to increase one's image acutance. This to me is a slight drawback.

While that may seem so, there are other, better, tools in RT for the creative 'sharpening' part. I place the word 'sharpening' between quotes, because it is not real sharpening, but acutance/local edge contrast enhancement rather than real sharpening.

What the RT developers collectively understood well, is that Capture sharpening, e.g. with the RL deconvolution, is a separate operation from the more creative, and usually less artifact prone, 'Contrast by Detail levels" controls which are more of a wavelet based detail enhancement. Once sharpness is restored, only (local) contrast is left to accentuate or reduce.

Cheers,
Bart
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TonyW

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Re: Sharpening
« Reply #19 on: October 30, 2015, 03:48:20 pm »

I would like to hear more on this.  I am sure others would also.
Well said, Bart....
Although I hate to do this but have to +1 to the above. 

Hi Bart
Call it what you will but obsession (or otherwise) to understand and make improvements is what makes the world go round and advance. 

Those that are prepared to work (and capable of understanding the fine details!),  freely share their findings and are open to discussion deserve our admiration or at least our attention.

BTW, is your server down as I was trying to access your article on image quality and sharpening (the one where the user inputs requirements)?
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