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Crisp look? Sharpening in LAB?

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  #21  
Old 04-05-2012, 09:33 AM
capice capice is offline
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Re: Crisp look? Sharpening in LAB?

I try to follow this with high interest..But isn't the question then..at what level is dataloss still exceptable...? Heaving in mind where the image will be used for...
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  #22  
Old 04-05-2012, 09:36 AM
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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 capice View Post
I try to follow this with high interest..But isn't the question then..at what level is dataloss still exceptable...? Heaving in mind where the image will be used for...
That is an impossible question to answer. There is always some data loss due to rounding errors in the numbers when you edit pixels. If you work high bit, it is moot, you have far more than you can ever use for output. Much depends on the image source, it’s qualities, what edits are applied and how, what the output device will be etc. It isn’t something to lose sleep over. But it is there. Calling an adjustment layer non destructive doesn’t change the rounding errors that result.
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  #23  
Old 04-05-2012, 12:47 PM
jhr jhr is offline
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Re: Crisp look? Sharpening in LAB?

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Originally Posted by andrewrodney View Post
Both are destructive, one gets burned onto the pixels as soon as you do it, the other when you print or flatten the image (which has to happen at some point). All adjustment layers do is let you change your mind and not use them. But at some point, the data has to be applied to the underlying pixels and then there is data loss.
Absolutely. That's what I mean. Sharpening in ACR and sharpening on a new layer in PS is just the same principle. Your applying the sharpness to the pixels. It's just that the latter method let's you change your mind more easily and that was what I was trying to explain.

Last edited by jhr; 10-08-2012 at 01:40 AM.
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  #24  
Old 04-05-2012, 12:49 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 JonathanHoglund View Post
Absolutely. That's what I mean. Sharpening in ACR and sharpening on a new layer in PS is just the same principle.
Not really. When you apply sharpening in ACR, until you render new, virgin RGB pixels, all you’ve done is made a set of instructions. You can alter and re-render anytime you wish. The RGB values are generated from all that data. Now yes, you could do something similar with an adjustment layer. You could delete it, rebuild it, make a change to opacity, but that set of data degrades due to rendering errors, the underlying data at some point.

One process builds virgin RGB pixels.
One process alters existing RGB pixel values.
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  #25  
Old 04-05-2012, 01:53 PM
jhr jhr is offline
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Re: Crisp look? Sharpening in LAB?

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Originally Posted by andrewrodney View Post
Not really. When you apply sharpening in ACR, until you render new, virgin RGB pixels, all you’ve done is made a set of instructions. You can alter and re-render anytime you wish. The RGB values are generated from all that data. Now yes, you could do something similar with an adjustment layer. You could delete it, rebuild it, make a change to opacity, but that set of data degrades due to rendering errors, the underlying data at some point.

One process builds virgin RGB pixels.
One process alters existing RGB pixel values.
Yes, you are absolutely right. One builds virgin RGB pixels, one changes pre-existing RGB values. No question about it. When using sharpness in ACR, the sharpness isn't applied to the actual RAW data. It is, as you say, a set of instructions. Still, you do end up with a image which has been rendered sharper than one that has been rendered without sharpness (since you have the ability to turn the Capture Sharpness settings off). That's my point. Developing with Capture Sharpness or sharpening a layer inside Photoshop. You end up with sharper pixels (sharper than a developed image rendered without Capture Sharpness applied). That's what I meant by them having the same principle (perhaps a blunt word choice). One could talk about the difference between sharpening inside Photoshop and sharpening in ACR and what happens to the image, but that wasn't my intent.

The intent of my first post was to talk about a scenario where one where you develop a RAW file with Capture Sharpness applied, do some cloning, realize that your settings used for the Capture Sharpness was a bit hars and then want to re-render what a different setting. That would impose a problem since there is no easy way to do that without having to do the cloning all over again. Otherwise you will end up with two different layers with two different sharpness levels (supposing that you do your cloning on a new layer).

Last edited by jhr; 10-08-2012 at 01:40 AM.
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  #26  
Old 04-05-2012, 05:20 PM
skoobey skoobey is offline
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Re: Crisp look? Sharpening in LAB?

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Originally Posted by kav View Post
Many people think this way. It's lying to you to a degree. I usually go in favor of leaving more detail that's a bit softer. With things that really do need to be removed, there are many ways to test that. If we're talking about a pimple, dust, scratches on a surface, etc. okay I'll give you that. Much of the time sharpening causes you to want to remove things that could have just stayed as slightly softer detail. I don't think it always looks better taking them out.
You couldn't have put it better. I do want to enhance the image, and I feel that by sharpening I am almost forced into removing additional detail in order for image to look tidy onc again.

So the general advice is to sharpen at the very end for the resoultion and medium on which it'll be displayed.

I should sharpen at various setting and then mask it out, putting that group of sharpening layers into luminosity blending mode? Right?

And I lost my train of thoughts. It was something about sharpening for print.
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  #27  
Old 04-06-2012, 03:48 PM
kav kav is offline
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Re: Crisp look? Sharpening in LAB?

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Originally Posted by andrewrodney View Post
Not really. When you apply sharpening in ACR, until you render new, virgin RGB pixels, all you’ve done is made a set of instructions. You can alter and re-render anytime you wish. The RGB values are generated from all that data. Now yes, you could do something similar with an adjustment layer. You could delete it, rebuild it, make a change to opacity, but that set of data degrades due to rendering errors, the underlying data at some point.

One process builds virgin RGB pixels.
One process alters existing RGB pixel values.
While you're technically correct, this works better on paper than in practice. I've tested it on a combination of testing grids and actual photos. If the photo is in poor focus or has camera shake issues, this is the time when it could make a difference. If it's a top quality image, the required sharpening might be significantly less either way, and it becomes either a non issue or nearly a non issue if it's applied later especially with improvements in the algorithms used over the days of photoshop 5 or so. Like I said it's better not to overdo it if this is going to be retouched further. It looks really ugly when someone sharpens a photo too much then ends up retouching details which now look somewhat rough due to the sharpening. There are things that people on here do to their images which produce far worse quantization errors. The threads on "split frequency" come to mind.

Speaking of that, I tested it to see if it would work well for helping retexture certain things like if you removed a lot of messy hair on someone's neck where there's just not enough skin data after the removal. I tested it pretty thoroughly and it does pretty much brutalize the data to the point where I wouldn't even suggest bothering with it at 8bpc. Before we get into that discussion again, you don't always choose what people give you.

On the topic of sharpening again... everything is destructive. When camera raw came out, there were arguments on what adjustments were applied prior to rendering. It's just one of those things. I wouldn't compromise your workflow just to apply as much sharpening as possible in raw processing. As I mentioned before, if you're going to do it there, you're better off going too low than too high. Not everyone is truly objective on the difference as sharpness is somewhat addictive, which is why I suggest going on the lighter side.
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  #28  
Old 04-10-2012, 01:59 AM
franko60 franko60 is offline
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Re: Crisp look? Sharpening in LAB?

I'm surprised nobody has mentioned sharpening on the K layer after converting to a wide gamut CMYK (profile available from curvemeister.com) as recommended by Dan Margulis. I've been sharpening this way for a few years now and can sharpen the hell out of an image without it looking oversharpened and without affecting the colour in any way.
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  #29  
Old 04-10-2012, 02:55 AM
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jarulex jarulex is offline
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Re: Crisp look? Sharpening in LAB?

Hello Folks! LAB color seem to be the trendy stuff or the 'it' color of the season, but can really give something different to the beauty retouch?
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  #30  
Old 04-10-2012, 08:47 AM
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Re: Crisp look? Sharpening in LAB?

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Originally Posted by franko60 View Post
I'm surprised nobody has mentioned sharpening on the K layer after converting to a wide gamut CMYK (profile available from curvemeister.com) as recommended by Dan Margulis.
Cause there is no such thing as a wide gamut CMYK space, CMYK is an output device dependant color space, moving from RGB to CMYK and back (or CMYK to CMYK) is not a very good idea!
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