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Author Topic: PK Sharpener Question  (Read 17723 times)

Jack Hogan

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Re: PK Sharpener Question
« Reply #80 on: June 28, 2013, 08:24:45 AM »

When you re-read the great article by Charles Cramer

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
« Last Edit: June 28, 2013, 10:43:10 AM by Jack Hogan »
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kirkt

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Re: PK Sharpener Question
« Reply #81 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
« Last Edit: June 30, 2013, 11:42:16 PM by kirkt »
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Temp

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Re: PK Sharpener Question
« Reply #82 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.
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Manoli

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Re: PK Sharpener Question
« Reply #83 on: October 26, 2015, 09:52:19 PM »

First off, my sincere apologies ...

Good first post.
Long on rhetoric but short on substance.
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Temp

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Re: PK Sharpener Question
« Reply #84 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.
« Last Edit: October 27, 2015, 06:57:00 AM by Temp »
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