C2P - Color Space question

[Martin Ocando]

Michael or Jeff, I just found a website where it explains lots of things about color management and bit depth, but this particular statement kind of tries to through away all beliefs about basic color space. And I quote:

..."Why not use a working space with the widest gamut possible?  It is generally best to use a color space which contains all colors which your final output device can render (usually the printer), but no more.  Using a color space with an excessively wide gamut can increase the susceptibility of your image to posterization.  This is because the bit depth is stretched over a greater area of colors, and so fewer bits are available to encode a given color gradation."...

The link can be found here: http://www.cambridgeincolour.com/tutorials/color-spaces.htm

Coming from Cambridge University I thought they should know what they are doing, but I think using ProphotoRBG is the way to go. In fact, Jeff said that by using ProphotoRGB posterization AND gamma clipping would be avoided.

Just to set things straight, I believe in what Jeff and Bill Atkinson says a 1000 times more than anybody else, but I wonder if they (cambridge) are wrong. Can you please enlighten me? Thanks  

[Schewe]

..."Why not use a working space with the widest gamut possible?  It is generally best to use a color space which contains all colors which your final output device can render (usually the printer), but no more.
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Well, right there is your answer...even Adobe RGB will clip colors you can both capture AND print. So, if you WANT to print those colors that Can be captured and be printed, then ProPhoto RGB is the color space. Sure, you can "play" with Beta RGB, Ekta RGB or any of the other variants, but the ONLY color space available with Camera Raw and Lightroom that fits that bill is Pro Photo RGB...

[digitaldog]

in addition, note that they say:

It is generally best to use a color space which contains all colors which your final output device can render (usually the printer)

A printer you'll use today or one in a year or 5 years? Look at the output gamut of just Epson ink jet printers in the last 3-5 years. At one time, Adobe RGB (1998) was sufficient and today its not. What will we be printing on in the future? Why funnel color your capture device was able to produce into something smaller?

[bjanes]

The link can be found here: http://www.cambridgeincolour.com/tutorials/color-spaces.htm

Coming from Cambridge University I thought they should know what they are doing, but I think using ProphotoRBG is the way to go. In fact, Jeff said that by using ProphotoRGB posterization AND gamma clipping would be avoided.
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Cambridge University was the academic home of Sir Isaac Newton, so it has a long heritage of excellence in disciplines underlying photography--color and optics. The Cambridge in Color website was created by Sean McHugh while he was conducting research for his PhD in chemical engineering at the university and the website is his own, and not an official university site. He is an amateur photographer and was a member of the Cambridge camera club (the Cambridge University Photographic Society).

Nonetheless, he is a gifted photographer, and his obvious high intelligence, ability to explain complex topics in understandable language, and scientific background allow him to make some very significant contributions to the photographic community. I post these comments because a few pros on this forum seem to think they know it all and the amateurs have nothing to contribute. In reality, both amateurs and pros can make meaningful contributions to the forum.

[DarkPenguin]

A dog post followed by a jane post.  Wonder what vegas had for the odds.

[Schewe]

A dog post followed by a jane post.  Wonder what vegas had for the odds.
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Ya ever see one dog lift a leg and then be followed by another dog sniffing and lifting his leg in the same spot?

And some "amateurs" seem to think that some "pros" can't think that amateurs can't (or don't) offer much in the way of contributions...not sure that comment was directed at Andrew or I (but I assume or presume it was) and I'm here to tell him that I have a lot more respect for amateurs than most pros... amateurs do things for the love of the game...pros only do it for money.

The only thing that may really distinguish an amateur from a pro is the relative intensity of experience. It's one thing to do things when you feel like it but another to HAVE to produce on a job. So, many times pros are more practical because there's really no excuse for not getting the job done, more or less on time. Amateurs have the luxury of repeated attempts to get it right over time because the only master they serve is themselves.

[bjanes]

A dog post followed by a jane post.  Wonder what vegas had for the odds.
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I do not know to whom DarkPenguin is replying, what he edited out of his original post, or for whom he carries water, but the post as makes no sense to me. Perhaps our avian friend would be would be better understood in Batman comic books.

Bill

[DarkPenguin]

I do not know to whom DarkPenguin is replying, what he edited out of his original post, or for whom he carries water, but the post as makes no sense to me. Perhaps our avian friend would be would be better understood in Batman comic books.

Bill
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I edited an 'n' out of the post.

[John.Murray]

. In reality, both amateurs and pros can make meaningful contributions to the forum.
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Including a bit of humor?

[Martin Ocando]

Well, right there is your answer...even Adobe RGB will clip colors you can both capture AND print. So, if you WANT to print those colors that Can be captured and be printed, then ProPhoto RGB is the color space. Sure, you can "play" with Beta RGB, Ekta RGB or any of the other variants, but the ONLY color space available with Camera Raw and Lightroom that fits that bill is Pro Photo RGB...
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Ok, but he says that if we use a very large space we risk posterization because there are not enough bits to represent the gradients. That's the part I don't get.

[Schewe]

Ok, but he says that if we use a very large space we risk posterization because there are not enough bits to represent the gradients. That's the part I don't get.
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Uh huh, well, based on 5 years' use of ProPhoto RGB I'll just say that ACTUAL experience indicates that really isn't a problem. So, unless you are willing to lose printable colors, you don't really have a choice, do you?

It's simple enough to test yourself...which is what everybody SHOULD do! Take an image and do the exact same processing in Adobe RGB & ProPhoto RGB and see if ANY negative impact shows in the PP RGB and compare the color and see if A RGB clips color. Do it right and you'll prove it to yourself.

[Martin Ocando]

Uh huh, well, based on 5 years' use of ProPhoto RGB I'll just say that ACTUAL experience indicates that really isn't a problem. So, unless you are willing to lose printable colors, you don't really have a choice, do you?

It's simple enough to test yourself...which is what everybody SHOULD do! Take an image and do the exact same processing in Adobe RGB & ProPhoto RGB and see if ANY negative impact shows in the PP RGB and compare the color and see if A RGB clips color. Do it right and you'll prove it to yourself.
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Actually I don't need to prove it, Jeff. Is simply a matter of having the exact knowledge to answer people who asks me what is the right way to do things.
Mostly JPEG shooters are bothered by color spaces, since I shoot exclusively RAW I try to "convert" JPEG shooters telling them that the beginning to deliver the best quality is a good capture in RAW.
You'll begin restraining the RAW data by forcing it into a color space. The broader the better. And as technology advances, better and better processing techniques can be applied to those RAWs. That is why I'm also converting my Pentax PEF files upon import in lightroom to DNG. I don't use Pentax built-in DNG format, since is not compressed.

Thanks for your wisdom  

[digitaldog]

Ok, but he says that if we use a very large space we risk posterization because there are not enough bits to represent the gradients. That's the part I don't get.
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That's why you want to be working in 16-bits. That said, Kodak who developed this space, and lots of users have found that this space does behave well in 8-bits (I'd however seriously suggest you still work in high bit).

[walter.sk]

That's why you want to be working in 16-bits. That said, Kodak who developed this space, and lots of users have found that this space does behave well in 8-bits (I'd however seriously suggest you still work in high bit).
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I've been using ProphotoRGB and working in 16 bits for some time now, andhave more leeway in the changes I can make before finding visible image deterioration.  

I recently started printing on an HPZ3100 and don't know if the printer actually prints a 16-bit file or converts it to 8-bit on the fly.  I have been printing from files with Prophoto RGB at 16-bits rather than convert to Adobe RGB and/or 8-bit color.  Any thoughts on that?

[digitaldog]

I recently started printing on an HPZ3100 and don't know if the printer actually prints a 16-bit file or converts it to 8-bit on the fly.  I have been printing from files with Prophoto RGB at 16-bits rather than convert to Adobe RGB and/or 8-bit color.  Any thoughts on that?
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In Photoshop, you're sending only 8-bits until that and other applications are updated for 16-bit output. In Leopard, and with the new Epson drivers, there's a new 16-bit check box but its not yet getting all that data from Photoshop. Maybe next version. Canon got around this using an Export module. ImagePrint, a 3rd party driver also sends 16-bit data.