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01-10-2010, 09:50 AM   #16
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my .02 ... convert to srgb from raw unless you plan to use a printer that is argb and you have a wide gamut screen; otherwise you're asking for a headache in making things look proper across 2 media.

01-10-2010, 09:54 AM   #17
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QuoteOriginally posted by Wheatfield Quote
Colourspace is assigned as part of raw conversion.
The OP has become aware that he doesn't know very much about colour management, but he doesn't yet understand how very little he understands, and so he is blaming the wrong thing.
As in thre conversion from nothjing to a RAW file when opened in say LR or from RAW file to jpg? I open RAW files in LR and see colour space nowhere. I must be missing something.
01-10-2010, 09:56 AM   #18
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QuoteOriginally posted by Alfisti Quote
As in thre conversion from nothjing to a RAW file when opened in say LR or from RAW file to jpg? I open RAW files in LR and see colour space nowhere. I must be missing something.
think of a raw as a tiff with a bunch of meta data unapplied, including the colorspace. it's assigned as part of the conversion to a format that can render on screen.
01-10-2010, 10:49 AM   #19
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QuoteOriginally posted by Alfisti Quote
As in the conversion from nothing to a RAW file when opened in say LR or from RAW file to jpg? I open RAW files in LR and see colour space nowhere. I must be missing something.
The default colourspace in Lightroom is ProPhoto RGB (the widest gamut available).
A colourspace has to be assigned during raw conversion for the process to happen.
All the colourspace is, is a set of definitions for what the individual pixel densities should look like.
If you shoot out of camera jpegs, then you are locked into either sRGB or aRGB by the in camera converter. If you shoot raw and convert as the first step of post processing, then you can assign pretty much any colourspace you want.
Generally, you want to start with the widest colourspace available and to your post processing in that space to avouid clipping colour, and then as the last step, convert to the colourspace that is best for the intended use, be it sRGB for computer monitor or printing with a conventional photolab, or a custom colourspace for some other purpose.

01-10-2010, 12:30 PM   #20
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QuoteOriginally posted by Alfisti Quote
I thought colour space was assigned in JPG or TIFF but not in RAW images? If so, how can you 'work' in aRGB or sRGB? It's surely just a matter of what you convert your image to after working on the RAW file yes?
You're absolutely right! However I tend to shoot in RAW+JPG all the time, and I typically end up using the JPG file unless I need to do some post processing to fix the image. However when I did convert my RAW files in the past, I also used Adobe RGB because of the mistaken belief that anything else was "inferior".

What's meant by "working" in Adobe RGB or sRGB is the workflow used to get from the source file to the final result, not necessarily just the processing you do to it. Sometimes this involves more than one application. If, at any step along your workflow you use anything but Adobe RGB (even as a final output result), then you're completely negating the use of Adobe RGB in the first place. This whole theory about "preserving the wider colorspace" doesn't make sense, because color management-aware applications (like Photoshop) process colors internally using the whole color space anyways.

QuoteOriginally posted by Wheatfield Quote
Colourspace is assigned as part of raw conversion.
The OP has become aware that he doesn't know very much about colour management, but he doesn't yet understand how very little he understands, and so he is blaming the wrong thing.
I guarantee you I know more about color management than you ever will.

QuoteOriginally posted by Wheatfield Quote
The default colourspace in Lightroom is ProPhoto RGB (the widest gamut available).
...
Generally, you want to start with the widest colourspace available and to your post processing in that space to avouid clipping colour, and then as the last step, convert to the colourspace that is best for the intended use, be it sRGB for computer monitor or printing with a conventional photolab, or a custom colourspace for some other purpose.
And that proves it right there. Your very statement contradicts itself.

Last edited by GoremanX; 01-10-2010 at 02:36 PM.
01-10-2010, 12:59 PM   #21
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QuoteOriginally posted by Alfisti Quote
I keep sayin goit but no one listends, aRGB is useless (even worse) unless you have an argb capable display, argb capable printer, argb capable paper etc etc etc and then you STILL need to ensure the image you create for web display is set to sRGB because most browsers don't support aRGB.

People keep saying I am nuts but again, it's about the workflow.
Alfisti,
Yep, our club just had a talk about fine art printing by a local professor who teaches photography.

Paper is not just paper, it has to be one of the papers certified for use in that printer, such as Epson, to print those colors correctly. To print aRGB, one must download the printer profile from a commercial company and install it on one's computer, etc.

In a word, horrifying.
01-10-2010, 08:21 PM   #22
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QuoteOriginally posted by GoremanX Quote
I guarantee you I know more about color management than you ever will.
Colour management is fundamental to obtaining consistent and accurate results and it's not rocket science, it's basically all done by the O/S and colour space aware apps these days, all that is required is a basic understanding of the principles of the system.

Welcome | dpBestflow

http://media-arts.rmit.edu.au/Les_Walkling/Colour_Management_Notes.pdf

Last edited by Peter Zack; 01-13-2010 at 01:55 PM.
01-10-2010, 10:50 PM   #23
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QuoteOriginally posted by distudio Quote
Colour management is fundamental to obtaining consistent and accurate results and it's not rocket science, it's basically all done by the O/S and colour space aware apps these days, all that is required is a basic understanding of the principles of the system.

Welcome | dpBestflow

http://media-arts.rmit.edu.au/Les_Walkling/Colour_Management_Notes.pdf
I said I was new to DSLR photography, not to graphic design. I was pushing Photoshop 4.0 to its limits before color management even existed. I spent years at an advertising agency in Montreal starting from 1997 as a graphic artist and web developer. Our department (Multimedia) used PCs, the Print Ad department used Macs. I still vividly remember the screams of frustration from the Print Ad department down the hall whenever one of our guys mangled the colors in a file because he overwrote the original on the server using a Windows-based app.

So when Photoshop 5.0 was released, it was seen as the perfect solution. Management quickly upgraded everyone to the latest Photoshop, and we all had to work in Adobe RGB from then on to maintain consistency between departments. Of course, this was just annoying for us web developers... we didn't NEED the wider color space! It's completely useless for our purpose! Most of the applications we used didn't even support it anyways, I was the only person in our department who used Photoshop. Now it was our turn to scream in frustration whenever the print department gave us source material in Adobe RGB. If we didn't convert to sRGB, we'd end up with colors that were way off and didn't match the customer's print ads.

(on a side-note, management also replaced my much-used Corel Draw with Adobe Illustrator around this time, and I pretty much gave up on vector graphics from that point on).

I don't dispute that Adobe RGB provides a wider color gamut. And I never said Adobe RGB doesn't have its place. What I said was, pictures right out of the camera that are taken with Adobe RGB (and this means JPGs, since RAW files have no colorspace) look like crap. I don't even need a fancy workflow to prove this point, just take a picture of something in each colorspace and look at it right there on your camera's screen. The Adobe RGB one looks like crap. Even if you repeat the same experiment with RAW instead of JPG, the Adobe RGB picture will still look like crap on your camera, because the embedded snapshot that the camera displays is a JPG anyways.

Adobe RGB is for a specific workflow where the final result is a 4-color print on an Adobe RGB-specific printer, and where every step between RAW and printout is performed with color management-aware applications that use Adobe RGB as a color profile. If, at any step of the way, even at the very end, you convert to sRGB, then there was no point in using Adobe RGB in the first place. It says it right there in that document you sent me a link to:

Page 4
"The aim of a colour managed work flow is to try and maintain the same colour on
all devices in the work flow, despite each device having a different colour gamut
that will represent the same colour numbers (64R128G192B) as a different colour."

The aim of color management is not to provide a wider "working" gamut which you can subsequently reduce at your convenience.

The following is a picture of a poster that I took. I picked this poster because it's very colorful and has a lot of gradients that go from green to blue, which is 90% of the improvement that Adobe RGB provides. This is the JPG from my K-7, with no post-processing:



Since I shoot in RAW+JPG, I also had the RAW file handy. So I opened it up in Photoshop CS2 and assigned it an sRGB colorspace. Then I edited the levels and applied an unsharp mask. Finally I saved it as a JPG:



Then I repeated the process, only this time I assigned an Adobe RGB colorspace when I opened the RAW file. I performed the same steps (levels, unsharp mask) and then converted the colorspace to sRGB before saving as a JPG:



The pictures are nearly identical, but there's a tiny shift in color tone from one to the other. You'd have to put them on top of each other and switch between them to see it. However, the picture that used the Adobe RGB profile is different from the poster on my wall because of that different tone. When I converted it to sRGB before saving it, it lost its color fidelity. The picture that stayed in sRGB throughout the workflow looks identical to the poster, especially the green of the visor and the yellow on the bent leg. Other than that, the gradients aren't any smoother in either picture, the contrast is the same in both, and the saturation is the same. I gained nothing by using Adobe RGB in my workflow, but I lost color fidelity.

If my goal had been to get the picture printed HUGE on an Adobe RGB printer, then I would've benefited by staying in that colorspace the whole time. Maybe then I would've seen an improvement in the smoothness of the gradients on the final printout. But for a computer screen? No, it just changed my colors. On a 4"x6" print? Unlikely to spot any benefits there, especially if I have to convert to sRGB before printing. On an 8"x10" using an Adobe RGB printer? ...at that point, Adobe RGB would probably be worthwhile. How often will I do this? Most likely never.

Here are the full size versions of those pictures above, for those who want to pixel-peep and compare:

sRGB workflow: http://lh3.ggpht.com/_HAZjMzZWrtc/S0pxznKCUsI/AAAAAAAABAo/3OFqaj8_2Jw/d/samus-srgb.jpg

Adobe RGB workflow (converted to sRGB before saving as JPG):http://lh5.ggpht.com/_HAZjMzZWrtc/S0pxao3YM0I/AAAAAAAABAg/YX14NgERxWE/d/samus-argb.jpg


Last edited by Peter Zack; 01-13-2010 at 01:54 PM.
01-11-2010, 02:06 AM   #24
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QuoteOriginally posted by GoremanX Quote
I said I was new to DSLR photography, not to graphic design. I was pushing Photoshop 4.0 to its limits before color management even existed. I spent years at an advertising agency in Montreal starting from 1997 as a graphic artist and web developer.
And I didn't say what I did, which was design, maintain, calibrate and fault find computer systems for graphic design agencies and pre-press houses. Dating back from when integrated colour management was in its infancy and before (ie Ventura Publisher + high res image substitution prior to ripping for the imagesetters). I also know Bill's employment background.

Unfortunately it appears that you've misunderstood the basic concept of colour management when you state:

"The aim of color management is not to provide a wider "working" gamut which you can subsequently reduce at your convenience."

Of course it's not the aim but to use a working colour space that is wider than the output device will always ensure that there is the least potential for clipping of the image colours. The basic aim of colour management by my reckoning is to provide consistency and predictability of colour reproduction from source to output.

You would be aware of course that modern DSLRs have a native gamut that its extraordinarily large compared to any current output device and that many new ink-jet printers have gamuts that exceed the AdobeRGB gamut. So even using an AdobeRGB work flow will cause clipping should the image contain hues outside the AdobeRGB gamut and but inside the printer gamut. Selection of the appropriate rendering intent will limit hue shift and will ensure that out of gamut colours are mapped to to target device gamut in order to provide a realistic colour gradient which is much preferred to hard clipping of the gamut over an out of gamut area.

The quoted paragraph below I am essentially in agreement with however maintaining the same colour throughout the system is not always a requisite, the colour management systems response can be tailored to the job by the selection of appropriate rendering intent.

Page 4
"The aim of a colour managed work flow is to try and maintain the same colour on
all devices in the work flow, despite each device having a different colour gamut
that will represent the same colour numbers (64R128G192B) as a different colour."

I wasn't aware that the rear camera display colour varies based on jpeg sRGB/aRGB selection, if that's the case the display system it just really poorly engineered, it shouldn't do that. I'll check it out later.

Of course some modern Web Browsers are colour space aware (such as the several recent versions of Firefox) so if you had embedded the appropriate colour space tags in your sample images instead of presenting them untagged they would have been rendered quite accurately in any colour space aware Browser (relatively ie discounting screen calibration or lack thereof).

Following is Web Browser Colour Space Rendering Diagnostic page that I cobbled together some time ago:

http://users.tpg.com.au/distudio/temp/ICC_test.html

Cheers,

Last edited by distudio; 01-11-2010 at 06:04 AM.
01-11-2010, 12:47 PM   #25
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QuoteOriginally posted by distudio Quote
And I didn't say what I did, which was design, maintain, calibrate and fault find computer systems for graphic design agencies and pre-press houses. Dating back from when integrated colour management was in its infancy and before (ie Ventura Publisher + high res image substitution prior to ripping for the imagesetters). I also know Bill's employment background.
Hey! There was probably one of your kind of guys setting up our equipment back in 1997!

If you're referring to Wheatfield, I couldn't care less what his employment background is.

QuoteOriginally posted by distudio Quote
Unfortunately it appears that you've misunderstood the basic concept of colour management when you state:

"The aim of color management is not to provide a wider "working" gamut which you can subsequently reduce at your convenience."

Of course it's not the aim but to use a working colour space that is wider than the output device will always ensure that there is the least potential for clipping of the image colours. The basic aim of colour management by my reckoning is to provide consistency and predictability of colour reproduction from source to output.
I will again quote from the very same document you mentioned to support your opinion:

Page 13
"Converting to a SMALLER colour space will compress the gamut of the image. When there
are many out-of-gamut colours the image’s maximum saturation and density scale will be
reduced and the image may become flat and dull."

My example in the previous post tends to support this. The editing I did to the picture in Adobe RGB colorspace brought some colors out of the gamut range of sRGB, so when I converted it to sRGB prior to saving as a JPG, some colors were re-mapped inaccurately and the picture ended up with a wrong overall tone.

QuoteOriginally posted by distudio Quote
You would be aware of course that modern DSLRs have a native gamut that its extraordinarily large compared to any current output device and that many new ink-jet printers have gamuts that exceed the AdobeRGB gamut. So even using an AdobeRGB work flow will cause clipping should the image contain hues outside the AdobeRGB gamut and but inside the printer gamut. Selection of the appropriate rendering intent will limit hue shift and will ensure that out of gamut colours are mapped to to target device gamut in order to provide a realistic colour gradient which is much preferred to hard clipping of the gamut over an out of gamut area.
Yes, cameras can capture an incredible level of color. But it doesn't really matter how many colors a digital camera can capture.

Most people's printers I've seen are $50 specials from Canadian Tire or Wal Mart. I wouldn't trust the printing accuracy on those even if they somehow covered the LAB range. Sometimes their accuracy changes when you buy new ink cartridges. At this point, color management becomes a joke. On the other hand, as has been stated many times, most commercial picture printers want documents in sRGB color space. Whether their printer supports the Adobe RGB range or not is irrelevant, because when they print, they assume sRGB anyways. If you give them a document in Adobe RGB, it will come out as bland as it does in an application that doesn't do color management.

QuoteOriginally posted by distudio Quote
I wasn't aware that the rear camera display colour varies based on jpeg sRGB/aRGB selection, if that's the case the display system it just really poorly engineered, it shouldn't do that. I'll check it out later.
As far as I know, ALL digital cameras display pictures in sRGB on playback. I don't think it's necessarily a limitation of the screen, because a color-aware playback application would do the conversion if that was the case (just like Photoshop does). Yet another drawback of using Adobe RGB... you can't even be sure if you captured the colors properly. This is precisely why I now shoot in sRGB and RAW+JPG. That way, the on-camera playback shows more accurate colours, and I still have the RAW file to do with as I wish should it become necessary.

QuoteOriginally posted by distudio Quote
Of course some modern Web Browsers are colour space aware (such as the several recent versions of Firefox) so if you had embedded the appropriate colour space tags in your sample images instead of presenting them untagged they would have been rendered quite accurately in any colour space aware Browser (relatively ie discounting screen calibration or lack thereof).
I was a web developer back before the web was taken seriously by anyone. This was in the days of Netscape 1.4, before Internet Explorer was used by anyone. And I worked in this field through the browser wars, suffering the havoc that it wreaked. As a result, I've learned the importance of catering to the "lowest common denominator". Most people do not have Adobe RGB-compatible web browsers. Of the ones that do, color management is most likely not enabled. It is still not enabled in Firefox by default, and I have the latest version. The only reason whether this matters is because of how OTHER people see my pictures. I don't want them seeing a bland, washed-out version of my picture. Personally, I don't use web browsers to review my own pictures. I have Gwenview, Showfoto and Digikam for that. So I leave my web browser configured to its default settings because I want to know exactly how other people will see my work (whether it's web development or photography).

And in the end, that's what all of this is about; the lowest common denominator. Most people on this forum are not professionals. Most of them do not print in Adobe RGB colorspace. Most of them don't even touch RAW files, they go straight for JPG. And those are exactly the people who read about the awesomeness of Adobe RGB and figure they must use it. Then they wonder (as I did) why their pictures keep coming out bland and lifeless.

If someone KNOWS he/she can make use of Adobe RGB to improve their pictures, then more power to them. But for the vast majority of us, it's a hindrance and an obstacle. At best it's an extra step that kills color fidelity. At worst it makes our pictures look terrible. If you won't be making use of it, Adobe RGB is a bad idea, and THAT's what the OP is all about.

I didn't even remember setting my camera to Adobe RGB! I just did it when I first got it, and then never looked at that setting again.
01-12-2010, 06:50 AM   #26
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GoremanX, if you have CS2 why aren't you using Smart Sharpen? time to move on from that old unsharpen mask

tip: .2 or .3 radius, 120-130%
01-12-2010, 12:26 PM   #27
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QuoteOriginally posted by attack11 Quote
GoremanX, if you have CS2 why aren't you using Smart Sharpen? time to move on from that old unsharpen mask

tip: .2 or .3 radius, 120-130%
I only just started using CS2, I've been using. 7.0 for endless years. I still haven't learned all these new things, I had no idea what Smart Sharpen was, I was a bit curious when I first saw it right under Unsharpen. I gave up on the graphic design career years ago and I only do it as a hobby now.

Thanks for the tip!
01-13-2010, 01:49 AM   #28
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Sorry for the late reply but I have been busy doing work ;-)

QuoteOriginally posted by GoremanX Quote
If you're referring to Wheatfield, I couldn't care less what his employment background is.
All I was alluding to is that it's foolhardy at best to write such things such as "I guarantee you I know more about color management than you ever will." if you have no idea of the skill set of the person to which you are referring.

QuoteOriginally posted by GoremanX Quote
I will again quote from the very same document you mentioned to support your opinion:

Page 13
"Converting to a SMALLER colour space will compress the gamut of the image. When there
are many out-of-gamut colours the image’s maximum saturation and density scale will be
reduced and the image may become flat and dull."

My example in the previous post tends to support this. The editing I did to the picture in Adobe RGB colorspace brought some colors out of the gamut range of sRGB, so when I converted it to sRGB prior to saving as a JPG, some colors were re-mapped inaccurately and the picture ended up with a wrong overall tone.
I'm not sure what you were doing wrong but there should be very little difference when an image is shot in AdobeRGB then converted to sRGB or shot in sRGB. Following is a wide gamut (ProPhoto RGB) image derived from a RAW file converted to both AdobeRGB and sRGB using Perceptual rendering intent in the colour conversion. All have embedded colour space tags and should render near identically in the latest Safari or FireFox Browsers (assuming colour management has not been disabled and rendering intent is set to 0 ie Perceptual). Of course only the sRGB image will appear at all realistic when viewed with a non-colour space aware Browser.

ProPhotoRGB



AdobeRGB



sRGB



QuoteOriginally posted by GoremanX Quote
As far as I know, ALL digital cameras display pictures in sRGB on playback. I don't think it's necessarily a limitation of the screen, because a color-aware playback application would do the conversion if that was the case (just like Photoshop does). Yet another drawback of using Adobe RGB... you can't even be sure if you captured the colors properly. This is precisely why I now shoot in sRGB and RAW+JPG. That way, the on-camera playback shows more accurate colours, and I still have the RAW file to do with as I wish should it become necessary.
You're correct I think (but the difference is not as significant as I expected), whether it really imposes such a difficulty is debatable though. The following images (intentionally blurred) are fixed WB images of the back of a K-x that was used to shoot a colour target under controlled lighting plus the differential of those images. The first was shot with the internal WB set at aRGB the second sRGB followed by the difference of the two.







QuoteOriginally posted by GoremanX Quote
If someone KNOWS he/she can make use of Adobe RGB to improve their pictures, then more power to them. But for the vast majority of us, it's a hindrance and an obstacle. At best it's an extra step that kills color fidelity. At worst it makes our pictures look terrible. If you won't be making use of it, Adobe RGB is a bad idea, and THAT's what the OP is all about.
Basically I agree that most people should simply leave their cameras set at the default JPEG colour space setting (in most all cameras is sRGB) but my argument is simply that it's becoming increasingly easy to manage a work-flow where either the source images or working colour space is not sRGB.

Most image editor packages are colour space aware, heck even lowly Picasa is (for JPEG images at least) and if the appropriate colour profile is loaded in the printer most packages will manage to produce a good print too. Granted many print kiosks and digital photo print services seem to totally ignore colour space, personally I would avoid them or at least make sure you pre-process files so that they print appropriately.

I personally think that a lot of the problems associated with colour space on the web is a direct function of the idiotic save for web action in some Adobe products. From recollection this function generally strips the colour space tag data as well as all other meta data. Given the intended use it should have been designed to suggest that the images should be most appropriately converted and saved as sRGB for web presentation.

Cheers,
01-13-2010, 04:10 AM   #29
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QuoteOriginally posted by distudio Quote
Sorry for the late reply but I have been busy doing work ;-)
Thank God! I thought you gave up because I was too argumentative. I'm really enjoying this debate, I'm learning (and re-learning) a lot.

QuoteOriginally posted by distudio Quote
All I was alluding to is that it's foolhardy at best to write such things such as "I guarantee you I know more about color management than you ever will." if you have no idea of the skill set of the person to which you are referring.
Perhaps, but if he can sit there and outright disregard my point of view without offering a different one in a civil manner (and without resorting to racial slurs), then his skill set is completely irrelevant. By far the worst Canadian I've ever had the displeasure of communicating with, and I usually have the utmost respect for my fellow Canadians.

QuoteOriginally posted by distudio Quote
I'm not sure what you were doing wrong...
Whelp, turns out my web browser had color management enabled all along. Those 3 pictures you posted all look exactly the same in Firefox. However when I download and open them with Gwenview, the Adobe RGB one looks nightmarishly dull, the ProPhoto one looks fantastic, and the sRGB one looks viciously over-saturated. I can't find any color management options for Gwenview, so I've disabled it as my default image viewer. I now use showFoto exclusively, since that supports color management and did display those 3 pictures identically (once I enabled color management explicitly).

In any case, I still maintain that not everyone has a color managed web browser, and when we post a picture on the web, our intended audience is people with web browsers who may or may not have have color management enabled. When it is NOT enabled, Adobe RGB pictures look like crap.

However, this made me wonder about the differences that I pointed out in my original post. Those differences are there, you can clearly see them for yourself. If the browser isn't to blame for those differences, what is? I did some further testing, and it turns out the camera itself is to blame! When set to Adobe RGB, my K-7 produces washed-out colours in its JPG files. It doesn't matter if I open the files in a web browser or in Photoshop, the Adobe RGB ones look bad compared to the sRGB ones. Somewhere in Pentax's color engine, it messes up the colors for JPG files in the Adobe RGB colorspace. After some testing, I've found that the same is true when converting to TIF files using the in-camera RAW tools. Regardless of how the image was originally shot, using the camera to assign an Adobe RGB colorspace to a final format ruins the output, while assigning an sRGB colorspace does not. I don't know if the DCU4 software does the same thing because I can't run it on my system.

Here's yet another example of the camera's output:

Camera's output in sRGB


Camera's output in Adobe RGB


Again, this is regarding FINAL FORMAT output, not RAW output. JPG from the camera is what most people end up using. However, the embedded JPG snapshot in RAW files gets affected in the same way. I'd say Pentax's Adobe RGB output is deficient, at least as far as the K-7 goes.

Developing the RAW file in Photoshop (or rather in Adobe Camara RAW) does result in identical-looking pictures when viewing them in a color management-aware application, even if the two are in different colorspaces. So you're totally right about that. I think the differences I showed in my poster example came from the fact that the histogram is different in each color space, so the image processing I did affected each image slightly differently depending on the working colorspace. Not necessarily better or worse, just different.

My original suggestion still stands: it's best to leave the camera set to sRGB. If one actually needs Adobe RGB, he/she should assign that to RAW files as they're developed... preferrably NOT using the camera's RAW processing tools.

QuoteOriginally posted by distudio Quote
Basically I agree that most people should simply leave their cameras set at the default JPEG colour space setting (in most all cameras is sRGB)
See? Even you said so!

One other thing I noticed while testing; the output of DCRAW (and therefore UFraw, Digikam, Gimp and everything else that depends on DCRAW) is identical to the camera's: bland, washed out colors in Adobe RGB, bright colors in sRGB. It almost makes me wonder what Pentax used to develop their in-camera RAW processing tools.

I'd love to know if DCU4 acts the same way.
01-13-2010, 05:47 AM   #30
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QuoteOriginally posted by GoremanX Quote
However when I download and open them with Gwenview, the Adobe RGB one looks nightmarishly dull, the ProPhoto one looks fantastic, and the sRGB one looks viciously over-saturated. I can't find any color management options for Gwenview, so I've disabled it as my default image viewer.
If this is the case I'd assume that it's somehow been set to ignore embedded colour space tags and renders image assuming a wide colour space such as ProPhotoRGB (but the adobeRGB rendering remains inconsistent with this theory). In any case this is not generally default behaviour for image view utilities.

QuoteOriginally posted by GoremanX Quote
In any case, I still maintain that not everyone has a color managed web browser, and when we post a picture on the web, our intended audience is people with web browsers who may or may not have have color management enabled. When it is NOT enabled, Adobe RGB pictures look like crap.
Indeed, unless web based images are intended for a very specific target group (with known capabilities) it's always preferable to present sRGB colour space images. But the fact is that colour space aware Browsers are now commonplace and eventually virtually all mainstream browsers will be colour space aware so the problem is diminishing on that front.

QuoteOriginally posted by GoremanX Quote
However, this made me wonder about the differences that I pointed out in my original post. Those differences are there, you can clearly see them for yourself. If the browser isn't to blame for those differences, what is? I did some further testing, and it turns out the camera itself is to blame! When set to Adobe RGB, my K-7 produces washed-out colours in its JPG files. It doesn't matter if I open the files in a web browser or in Photoshop, the Adobe RGB ones look bad compared to the sRGB ones.
Your new sample images (crayon set) present very similarly in my Firefox Browser and both load in Photoshop looking fine. In my Photoshop "Color Management Policies" preferences I have selected "Preserve Embedded Profiles" for RGB images and all the "Ask when opening" boxes are ticked, so on import to Photoshop I simply confirm "Use embedded profile" as there's little to be gained converting images to my wider gamut default working space (ProPhotoRGB).

When I loaded the aRGB image and converted to "sRGB" profile the saved image looked virtually identical your sRGB version in any of my image Browsers. So I don't really see any problem with the cameras output, I would suggest that you may have a problematic colour management work-flow setting.

QuoteOriginally posted by GoremanX Quote
My original suggestion still stands: it's best to leave the camera set to sRGB. If one actually needs Adobe RGB, he/she should assign that to RAW files as they're developed... preferrably NOT using the camera's RAW processing tools.

See? Even you said so!
Ah yes, but photographers participating in fora such as this generally appear to be interested in maximising the quality of the output of their equipment, print especially (and there can definitely be visible benefits to fully utilising a printers gamut). So surely photographers interested in making the most of their equipment would be wise to familiarise themselves with the fundamentals and practicalities of the now embedded colour management systems? :-)

Cheers,
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