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Crisp look? Sharpening in LAB?

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  #41  
Old 04-17-2012, 11:48 AM
skoobey skoobey is offline
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Re: Crisp look? Sharpening in LAB?

Would you guys/gals slow down, I'm actually tryng to read all of this.
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  #42  
Old 04-17-2012, 12:35 PM
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Mike Needham Mike Needham is offline
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Re: Crisp look? Sharpening in LAB?

Cheers Andrew, more than I could have hoped for.
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  #43  
Old 04-17-2012, 05:39 PM
franko60 franko60 is offline
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Re: Crisp look? Sharpening in LAB?

Quote:
Originally Posted by andrewrodney View Post
You plot this gamut in 3D as I did? If so, you should re-examine the idea it is wide gamut. Itís a tad smaller in overall gamut than Adobe RGB (1998)* which is pretty wide for a CMYK space but inadequate in gamut size for all kinds of work.

*Gamut volume 1188820 vs, 1207529.
Well, I'm always ready to be educated and frankly I wouldn't know how to plot it in 3D. However, pretty much all my work is output either to sRGB for the web or CMYK for offset printing and it seems that you're saying that the CMYK is a wider gamut than either of these? If so, I lose nothing by converting from RGB to WGCMYK and back again, and gain the advantage I mentioned before.

I understand it may not be suitable for all workflows and all output situations, but then, nothing is, is it? All I can say is as a photographer it gives me an output that my clients are satisfied with and have been for many years (I've been capturing digitally since 2000). I do capture and archive in RAW so I can go back to the original data for specific situations but as a day to day sharpening tool it works well for me in my situation.
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  #44  
Old 04-17-2012, 05:46 PM
franko60 franko60 is offline
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Re: Crisp look? Sharpening in LAB?

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Originally Posted by andrewrodney View Post
I donít want any color artifacts.
Now you're being pedantic. I'm unwilling to speak in absolutes in any situation, but let me say by sharpening on the black channel I don't get any additional colour artefacts. I'm going to get colour artefacts when I convert to jpeg anyway, aren't I? Or am I wrong about that?

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I donít want to spend time converting color spaces to conduct an edit I donít have to. This idea being sold on the site is a solution in search of a problem.
Well, it was Dan Margulis who first sold this idea, not me and not the owners of this web site. Dan quoted this site in his article in Photoshop User.

I'll be the first to admin that I'm not a technical wizard although I've used PS since v3. I'm a working photographer (and have been for 30 years) and when someone like Margulis shows me a new technique and explains why it's a great solution I listen (or read in this case) and take note.
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  #45  
Old 04-17-2012, 05:59 PM
franko60 franko60 is offline
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Re: Crisp look? Sharpening in LAB?

Thanks for the detailed explanation, Andrew, although I must confess you lost me a bit there.

Just one question - at the end of the day, for all practical purposes and for 99% of the work we photographers put out, does it really make that much difference? I mean, as I said, most of my work these days is destined for the web. Since there's no way to determine what the colour calibration is of the monitor or device the person sees it on, isn't it all a bit theoretical? Sharpening makes a big different to what is seen; does super accurate colour really make that much difference?
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  #46  
Old 04-17-2012, 06:20 PM
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andrewrodney andrewrodney is offline
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Re: Crisp look? Sharpening in LAB?

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Originally Posted by franko60 View Post
Well, I'm always ready to be educated and frankly I wouldn't know how to plot it in 3D.
You have to have the tools, hence it is better to examine the so called wide gamut CMYK file than to believe what you read on a site selling a product. This is a pretty wide gamut for CMYK, it isnít at all for RGB. FWIW, I plotted the CMYK space and got the gamut volume using ColorThink Pro from CHROMIX.

Quote:
However, pretty much all my work is output either to sRGB for the web or CMYK for offset printing and it seems that you're saying that the CMYK is a wider gamut than either of these?
This space is wider than most CMYK output spaces but until you provide an ICC profile of the conditions, it is impossible to say if it would fully contain another CMYK space or if only some portions of the space are wider. It is wider than sRGB (which ainít that wide). IF your work is designed only for output to sRGB, there is little point in even using this space. But then there is little point in converting to CMYK just to sharpen an image. At least Iíve yet to be shown this as fact.

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If so, I lose nothing by converting from RGB to WGCMYK and back again, and gain the advantage I mentioned before.
Of course you do. Any conversion from one space to another loses something: data and it takes time. And since you are going RGB to CMYK and presumably back, instead of just converting to CMYK for your actual output needs and then sharpening, you are conducting an extra conversion.

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I understand it may not be suitable for all workflows and all output situations, but then, nothing is, is it?
Actually Iíve shown the data loss and color loss doing this. So now it is up to the ďI have to convert to CMYK just to sharpenĒ proponents to prove that workflow is even useful! Iíve yet to see this. I know someone wrote converting to CMYK to sharpen the K channel exists and I know someone is selling a plug-in along with the misnomer (wide gamut CMYK) but so far, Iíve seen nothing that illustrates this is necessary.

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All I can say is as a photographer it gives me an output that my clients are satisfied with and have been for many years
That doesnít wash since you apparently didnít also show them output using what many of us consider a more appropriate workflow. If youíve never had a Waguy Beef hamburger, a MacDonalds burger seems to be as tasty as you can imagine. So besides the time and data loss using this workflow, can you or someone else illustrate it is actually producing a better result than a process that is faster and doesnít requires two color space conversions?

As my dear friend Bruce Fraser (who forgot more about sharpening than most people actually know) once said:ďYou can do all sorts of things that are fiendishly clever, then fall in love with them because they're fiendishly clever, while overlooking the fact that they take a great deal more work to obtain results that stupid people get in half the time. As someone who has created a lot of fiendishly clever but ultimately useless techniques in his day, I'd say this sounds like an example."

I think his quote perfectly describes this CMYK sharpening process. But if someone can provide a series of experiments that clearly illustrate other workflows are indicative in comparisons, Iím all ears.

Quote:
(I've been capturing digitally since 2000).
And Iíve been using Photoshop since May 1990 (Bruce was using it before it was even called Photoshop). So what?
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  #47  
Old 04-17-2012, 06:26 PM
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andrewrodney andrewrodney is offline
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Re: Crisp look? Sharpening in LAB?

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Originally Posted by franko60 View Post
Just one question - at the end of the day, for all practical purposes and for 99% of the work we photographers put out, does it really make that much difference? I mean, as I said, most of my work these days is destined for the web.
That is an impossible question to answer because for 99% of photographers and others, we donít know the final output in the future. If you start with more data from capture and raw conversion and disgard that data, it is gone forever. If you know for a fact the image will only go to the web, then for the time being, sRGB is fine. Notice I say for the time being. The reason sRGB is used for web viewing is because today, the vast majority of displays kind of behave close to sRGB. But there are wide gamut displays being sold and in a non ICC aware browser, sRGB looks piss poor (just like Adobe RGB looks piss poor on an sRGB display in a non color managed browser). Consumers like saturated colors. Iím fairly certain, as the price for wide gamut displays come down in price, they will become the norm and hence, sRGB images will look piss poor. Or maybe weíll finally see everyone viewing web images use a color managed browser.

Point is, most of us donít know what or where our images will be in 10 years. Why throw away the data when it is easy and safe to save off an iteration in sRGB for now? And youíll have to save off an iteration anyway. Even my iPhone produces photoís that are too large for the web. I have to size them down. If Iím doing this, saving out to sRGB from a wider gamut capture isnít any more work.

For 99% of the work photographers produce to differing media, sRGB is far from ideal. That doesnít mean the sRGB version will look like crap but it means it will not look as good as it could look. And if you are making fine quality ink jet prints for a book or the wall, even Adobe RGB falls short compared to a modern 8-10 color ink jet.

Why place a 35mm back on a 4x5?
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  #48  
Old 04-17-2012, 06:34 PM
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andrewrodney andrewrodney is offline
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Re: Crisp look? Sharpening in LAB?

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Originally Posted by franko60 View Post
Well, it was Dan Margulis who first sold this idea, not me and not the owners of this web site. Dan quoted this site in his article in Photoshop User.
The site I refer to is the one with the questionable wide gamut CMYK profile to implement what I think is an equally questionable Margulis workflow (and yes, Iíve sharpened CMYK images, a lot. But the CMYK was sized and output ready in a CMYK space intended for that print process).

Quote:
and when someone like Margulis shows me a new technique and explains why it's a great solution I listen (or read in this case) and take note.
Take note and test! Trust but verify. You assume Dan did? I donít know....

And to read something like this and blindly believe it is a good idea is kind of folly. Hence my suggestion people test various workflows properly. Along with examining the potential pitfalls of doing things like converting from RGB to CMYK and back just to sharpen an image and the data loss that might show up. Youíll notice that with one image, I provided exact data as to the number of unique colors prior to and after this technique. If you donít care you are throwing away more than 6% of the unique colors just to sharpen a black channel, fine. But at least illustrate that not doing this will result in an inferior document due to sharpening in RGB. Lets see some proof.
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  #49  
Old 04-17-2012, 07:12 PM
franko60 franko60 is offline
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Re: Crisp look? Sharpening in LAB?

Andrew, thank you for taking the time to argue and explain all the various questions I've raised. I don't think too many people would have that much patience and integrity. I guess I did rather think, "Gee, that's neat" when I first read Margulis' article and maybe it was back then. But things do move forward, with blinding rapidity, and what holds true 5 years ago doesn't necessarily hold true today. Keeping up for somebody who, at the end of the day, isn't that technically oriented or interested in the nuts and bolts of how things work but rather just wants to know that they do work is a difficult endeavour.

Again, thank you.

Quote:
Why place a 35mm back on a 4x5?
Well I did it in order to shoot Kodachrome, which never did come out in 4x5
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  #50  
Old 04-17-2012, 07:14 PM
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andrewrodney andrewrodney is offline
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Re: Crisp look? Sharpening in LAB?

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Originally Posted by franko60 View Post
Well I did it in order to shoot Kodachrome, which never did come out in 4x5
What, no 120 back for that camera? <g>

Ah Kodachrome, I remember it well.
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