Posted by Steve Sieren on November 19, 2008 at 11:26 PM
I was introduced to it over the weekend and heard it was a good idea to use. When I make the change the colors oversaturate instantly. When I convert to jpeg it desaturates?
Anyone care to elaborate on this?
Posted by David Bostedo on November 19, 2008 at 11:49 PM
ProPhotoRGB is a very large color space....the range of colors it defines aren't likely to be able to be shown on your monitor, and colors that likely can't be printed. The main reason to use it, as far as I know, is to get the largest possible range of colors in your images - all the colors your camera can possibly capture. Since other color spaces are smaller, they tend to not quite be able to show all the colors you can view or print.
The problem is that ProPhoto goes outside the range you can see on your monitor. You may have a color defined that the monitor is clipping to be the closest it can get.
If you have an image with colors that easily fit in sRGB or AdobeRGB, then developing the RAW file in ProPhotoRGB shouldn't make a difference. It's when the camera captures colors outside these color spaces that you should see a difference. Here's a bunch more detail from Luminous Landscape. (A great site if you're unfamiliar with it - I'd suggest reading everything on there in the tutorials, techniques, understanding, and essays sections.)
As to your particular problem, when you say you are "making the change" you need to be more specific. I'm assuming you have a TIFF that's already in another space? Are you converting to ProPhotoRGB, or assigning ProPhotoRGB? You should be converting, which, depending on rendering intent, will attempt to keep the image looking the same by changing the color data in the file. Assigning will simply re-read the color data as though it's in the new color space, which can do some weird things.
In general, if you want to use ProPhotoRGB, you should probably be using it straight out of the RAW converter. Otherwise, you're losing much of the benefit, and might be causing headaches if you do a lot of adjustment. (Actually, the headache part is always possible, but can be worked around with proper conversions and soft-proofing.)
And as far as converting to JPG, I'm guessing that since it's 8-bit, it's also not capable of representing the larger color space, but I'm not certain of that.
Posted by Robert Fisher on November 20, 2008 at 8:52 AM
As David said, ProPhoto is a much wider gamut than AdobeRGB. It's what I use as my working space, for whatever that matters. I use it because I want to be able to take advantage of advancements in technology. As monitors improve and printers improve, reproduction of wider gamuts will be possible. Some printers on the market can already reproduce more than AdobeRGB in some colours. Some might say just use AdobeRGB now then go back and reprocess the RAW file in the future. That's more work though and it's unnecessary.
Same question as David, when you say you "switched" what do you mean? Using Assign Profile will radically change the appearance of the colours. Using Convert to Profile is what you want to use. Just as when you save an image for the web you would convert it to sRGB, not assign sRGB.
If you've got an image in, say, AdobeRGB already and convert to ProPhoto there's no benefit. You can't create colour that didn't exist. Once you make the choice of AdobeRGB or sRGB you can't go to a wider gamut and gain the benefit. Rendering intent plays no part. These are what are termed as device independent colour spaces. There is no rendering intent when switching between them. Rendering intent only plays a part in device dependent colour spaces (monitor profiles, printer profiles for example).
When you say the images become desaturated when you save them as JPEGs, how are you doing it? Are you using Save for Web? Are you converting to sRGB? The drop from 16 bit (if that's what the originals were) to 8 bit won't make a difference. The upper and lower limits are the same, it's just what's in the middle that's different. Gradation will be affected, but overall colour saturation shouldn't be.
Posted by Steve Sieren on November 20, 2008 at 1:53 PM
Thank you guys. I meant when once I convert to photo pro rgb in camera raw the colors seem to oversaturate.
You know what I'm sorry I was trying to open a file that was tiff that was open with Canon's 5d software that opens up out of the zoom browser. I guess its called image task. So I must have because of already being convert to tif in that software.
That software doesn't offer photo pro rgb. I have light room 2 & CS3.
I sometimes like the landscape setting in that software(image task) but I can probably live without it.
Do any you use that software? Should It just be using LR2 or Camera Raw in Cs3 to take advantage of Photo pro rgb?
My 5D has been set to adobe rgb and only offers srb other than that.
I appreciate the help guys.
Posted by Steve Foss on November 20, 2008 at 2:34 PM
Steve, I would just use ACR in Photoshop (or LR2) to convert a RAW image to a ProPhotoRGB TIFF file. You can do it in either.
Posted by Robert Fisher on November 20, 2008 at 3:46 PM
The choice of a colour space in camera only affects JPEGs. RAW files have no colour space. This is why choosing ProPhoto when you convert your RAW files to TIFF allows you to retain as much colour as possible that your camera captured.
If you're seeing a marked drop in saturation when you convert from ProPhoto to sRGB that means that the colours in the scene you captured are wider than the sRGB gamut. It's not a problem, it's just the conversion from the wider gamut to the smaller.
I made a misstatement earlier regarding rendering intents too. I said rendering intent doesn't matter for device independent colour spaces. That's true but not complete. For device independent colour spaces like working spaces, the default rendering intent is Relative Colorimetric and choosing another intent won't make a difference.
I've not used ZoomBrowser but Canon's Digital Photo Pro software doesn't offer ProPhotoRGB either. Interestingly, it offers Wide Gamut RGB which is rarely used. Wide Gamut is only slightly smaller than ProPhoto so if you wanted to use it out of the DPP software, you wouldn't lose much at all compared to ProPhoto but you'd gain a fair bit compared to AdobeRGB.
And yeah, same as Steve, I'd suggest setting ProPhotoRGB as your default for exporting images in LR and you're set.
Posted by David Bostedo on November 20, 2008 at 4:32 PM
You can't create colour that didn't exist.
Well, sort of - if you take an image in sRGB, convert it to ProPhotoRGB, and really push things around in PS you can still create colors that couldn't have existed in the sRGB image. You could also create colors that can't be shown on your monitor that way, and you can create colors that the camera couldn't have captured.
These things are probably unlikely, but possible.
Posted by Steve Sieren on November 20, 2008 at 5:15 PM
It all seems so much more complicated if a person tends to ignore it all. I get it now and I'm glad I can still use the DPP software if I'd like with out much loss. Thanks for you help David, Robert and Steve.
Discussion
7 repliesAnyone care to elaborate on this?
The problem is that ProPhoto goes outside the range you can see on your monitor. You may have a color defined that the monitor is clipping to be the closest it can get.
If you have an image with colors that easily fit in sRGB or AdobeRGB, then developing the RAW file in ProPhotoRGB shouldn't make a difference. It's when the camera captures colors outside these color spaces that you should see a difference. Here's a bunch more detail from Luminous Landscape. (A great site if you're unfamiliar with it - I'd suggest reading everything on there in the tutorials, techniques, understanding, and essays sections.)
As to your particular problem, when you say you are "making the change" you need to be more specific. I'm assuming you have a TIFF that's already in another space? Are you converting to ProPhotoRGB, or assigning ProPhotoRGB? You should be converting, which, depending on rendering intent, will attempt to keep the image looking the same by changing the color data in the file. Assigning will simply re-read the color data as though it's in the new color space, which can do some weird things.
In general, if you want to use ProPhotoRGB, you should probably be using it straight out of the RAW converter. Otherwise, you're losing much of the benefit, and might be causing headaches if you do a lot of adjustment. (Actually, the headache part is always possible, but can be worked around with proper conversions and soft-proofing.)
And as far as converting to JPG, I'm guessing that since it's 8-bit, it's also not capable of representing the larger color space, but I'm not certain of that.
Same question as David, when you say you "switched" what do you mean? Using Assign Profile will radically change the appearance of the colours. Using Convert to Profile is what you want to use. Just as when you save an image for the web you would convert it to sRGB, not assign sRGB.
If you've got an image in, say, AdobeRGB already and convert to ProPhoto there's no benefit. You can't create colour that didn't exist. Once you make the choice of AdobeRGB or sRGB you can't go to a wider gamut and gain the benefit. Rendering intent plays no part. These are what are termed as device independent colour spaces. There is no rendering intent when switching between them. Rendering intent only plays a part in device dependent colour spaces (monitor profiles, printer profiles for example).
When you say the images become desaturated when you save them as JPEGs, how are you doing it? Are you using Save for Web? Are you converting to sRGB? The drop from 16 bit (if that's what the originals were) to 8 bit won't make a difference. The upper and lower limits are the same, it's just what's in the middle that's different. Gradation will be affected, but overall colour saturation shouldn't be.
You know what I'm sorry I was trying to open a file that was tiff that was open with Canon's 5d software that opens up out of the zoom browser. I guess its called image task. So I must have because of already being convert to tif in that software.
That software doesn't offer photo pro rgb. I have light room 2 & CS3.
I sometimes like the landscape setting in that software(image task) but I can probably live without it.
Do any you use that software? Should It just be using LR2 or Camera Raw in Cs3 to take advantage of Photo pro rgb?
My 5D has been set to adobe rgb and only offers srb other than that.
I appreciate the help guys.
If you're seeing a marked drop in saturation when you convert from ProPhoto to sRGB that means that the colours in the scene you captured are wider than the sRGB gamut. It's not a problem, it's just the conversion from the wider gamut to the smaller.
I made a misstatement earlier regarding rendering intents too. I said rendering intent doesn't matter for device independent colour spaces. That's true but not complete. For device independent colour spaces like working spaces, the default rendering intent is Relative Colorimetric and choosing another intent won't make a difference.
I've not used ZoomBrowser but Canon's Digital Photo Pro software doesn't offer ProPhotoRGB either. Interestingly, it offers Wide Gamut RGB which is rarely used. Wide Gamut is only slightly smaller than ProPhoto so if you wanted to use it out of the DPP software, you wouldn't lose much at all compared to ProPhoto but you'd gain a fair bit compared to AdobeRGB.
And yeah, same as Steve, I'd suggest setting ProPhotoRGB as your default for exporting images in LR and you're set.
Well, sort of - if you take an image in sRGB, convert it to ProPhotoRGB, and really push things around in PS you can still create colors that couldn't have existed in the sRGB image. You could also create colors that can't be shown on your monitor that way, and you can create colors that the camera couldn't have captured.
These things are probably unlikely, but possible.