PhotoPro RGB Gamut Issues

[Boatman]

Very recently I changed my ACR settings to open in Photopro RGB instead of Adobe RGB. Immediately I noticed some strange things going on with images created this way on both the web and in Picasa. I posted the following item here on CiC and noted that the coloration was wrong. C & C On Image

Having noted that my Picasa images were now also messed up, both in Picasa and on Picasweb, I decided I need to look into this further. I posted a note on the Picasaweb forum and quickly Tom O'haver with Google responded back stating that I had a color gamut issue. I put two and two together and figured out that my move to Photopro was the culprit. You can see some examples of this by going to the link:
https://picasaweb.google.com/1087441.../201201Exeter#
Oddly, the thumbnails on Picasaweb show the colors correctly for both Photopro and aRGB. The desktop version of Picasa cannot display either the thumbnail or the full image correctly with Photopro RGB.

My question is, If I want to use Photopro, how do I convert back to an aRGB or sRGB gamut for Picasa and web display? Clearly simply converting from 16-bit to 8-bit and making a .jpg does not correct the colors to a gamut that can be correctly displayed.

[Neelly]

If you have Photoshop 'Save For The Web & Devices' automatically converts to sRGB and resizes if desired.

[Colin Southern]

If I want to use Photopro, how do I convert back to an aRGB or sRGB gamut for Picasa and web display?

Edit -> Convert to Profile (choose sRGB as destination profile)

Note: Use CONVERT, not assign.

PS: Very little point in using Prophoto as the monitor can't display the additional colours (if there are any), and no printer will be able to print many of them.

[Macmahon]

If you convert to sRGB as Colin suggests, you'll desaturate the most saturated colours in your images. and all others proportionately, to fit into the sRGB colour space. In other words, the colours in your image will no longer be exactly the colours you shot. If that's OK (e.g. you don't intend to print) then it's very sensible, because sRGB is a small enough colour space that all it's colours can be displayed on even the lowliest monitor. For more detail on what the trade off's are, look at:

http://fromcameratoprint.com/Referre...e%20plots.html

If you don't convert, and someone (or someone's gear) interprets your ProPhoto numbers as sRGB, then what they see will be c..p and your reputation may suffer!! I've been there!


Cheers
Tim

[DanK]

The other reason not to work in sRGB is that it gives you less headroom for editing changes. It's very simple to keep ProPhoto as your working space and then convert at the end, as needed. For the web, always convert to sRGB. For labs, follow their directions (e.g., Bay Photo accepts either sRGB or aRGB, if I remember right). For printing yourself, you may not have to convert at all. I print from Lightroom, even when I have edited in Photoshop as well, and LR automatically maps to the color space appropriate for your printer (if you have the software, not the printer, managing color). With an inexpensive printer, I did once have problems printing from ProPhoto in photoshop, but if that happens, just convert then to aRGB and print.

[Neelly]

The other point to bear in mind that a good monitor, LaCie 700 series, for example will show somewhere about 123% of the AdobeRGB colour space and the difference is amazing. Now I know they are expensive but how many people on this site will quite happily drop £1500 or more on a lens or camera and then are quite happy to view the results on a £120 monitor.

[Colin Southern]

If that's OK (e.g. you don't intend to print) then it's very sensible, because sRGB is a small enough colour space that all it's colours can be displayed on even the lowliest monitor.

Hi Tim,

There's another archillies heel too, unfortunately ...

If one is doing their own printing, or having it done at a high-end shop then it may be possible to utilize something in excess of the sRGB gamut - but the normal off-the-street print shops invariably seem to work in sRGB.

I might add that for the life of me, I can't understand how we can put men on the moon over 40 years ago and talk to them, but in 2012 we still can't get software in machines in off-the-street print shops to detect when a profile mismatch is about to occur

[Simon Garrett]

As Colin implied, it's important to make sure that the image is converted (not assigned) to sRGB at some point in the workflow before hosting on a web site.

Macmalon said:

If you convert to sRGB as Colin suggests, you'll desaturate the most saturated colours in your images. and all others proportionately, to fit into the sRGB colour space. In other words, the colours in your image will no longer be exactly the colours you shot.

That's true, but I think it's a bit misleading. In the image being converted, colours outside sRGB will be desaturated to fit within sRGB - true. However, in most images, most (sometimes all) pixels are within sRGB. These will be altered little or not at all, depending on rendering intent. In other words, most images, after conversion from ProPhoto to sRGB, will look almost identical (provided you're using colour-managed software, and the monitor is properly calibrated and profiled with a hardware device). Only very highly saturated colours - relatively uncommon in nature - will be altered.

Colin said:

Very little point in using Prophoto as the monitor can't display the additional colours (if there are any), and no printer will be able to print many of them.

Quite so: most monitors can't display anything beyond sRGB (so conversion between ProPhoto and sRGB will make no visible difference).

Just to emphasise the point: most photos don't have many (if any) pixels with colours beyond sRGB. I have two monitors: one wide gamut (roughly Adobe RGB) and one "normal" gamut, approximately sRGB. Of my 25,000 raw images in Lightroom, most look almost the same on the two monitors. I have to look for the small proportion with very saturated colours. I can create images in Photoshop with mega-saturated colours beyond sRGB, and sure - they look different. But most photos look the same.

Nothing wrong with using ProPhoto RGB (I use Lightroom, which always uses ProPhoto - there's no choice) and it will maximise the possibility of printing the brightest colours on photo printers, most of which can go beyond sRGB. But if you use anything except sRGB, IMHO you really need to make sure you have a properly colour managed workflow. And you need to work in 16 bit - in 8 bit ProPhoto the quantisation steps between adjacent levels can be visible.

[Simon Garrett]

...for the life of me, I can't understand how we can put men on the moon over 40 years ago and talk to them, but in 2012 we still can't get software in machines in off-the-street print shops to detect when a profile mismatch is about to occur

Nor me! Trouble is, IMHO, no one really designed colour management. It's just sort of grown bit-by-bit as different people have added incomplete (and often incompatible bits) to solve their immediate problem, leaving the whole as a rather untidy mess.

[Colin Southern]

Nor me! Trouble is, IMHO, no one really designed colour management. It's just sort of grown bit-by-bit as different people have added incomplete (and often incompatible bits) to solve their immediate problem, leaving the whole as a rather untidy mess.

I'd settle for just a popup that said "This image appears to be in the Prophoto colourspace - Colourcast Photo Prints recommend using sRGB to as least give your photo a fighting change with our crappy printing equipment"

[Macmahon]

Hi Tim,


I might add that for the life of me, I can't understand how we can put men on the moon over 40 years ago and talk to them, but in 2012 we still can't get software in machines in off-the-street print shops to detect when a profile mismatch is about to occur

Colin

I couldn't agree more! It drove me so crazy I invested heaps in doing it all myself! Now I'm a happy camper

Tim

[Colin Southern]

Colin

I couldn't agree more! It drove me so crazy I invested heaps in doing it all myself! Now I'm a happy camper

Tim

Same here. Honestly, there are two "main players" in town, and frankly (putting it politely) "they're just not geared up for quality results". Do them all myself now - and wouldn't have it any other way.

[Macmahon]

. ...... As Colin implied, it's important to make sure that the image is converted (not assigned) to sRGB at some point in the workflow before hosting on a web site.

Just to emphasise the point: most photos don't have many (if any) pixels with colours beyond sRGB. I have two monitors: one wide gamut (roughly Adobe RGB) and one "normal" gamut, approximately sRGB. Of my 25,000 raw images in Lightroom, most look almost the same on the two monitors. I have to look for the small proportion with very saturated colours. I can create images in Photoshop with mega-saturated colours beyond sRGB, and sure - they look different. But most photos look the same.
....

Hmmm. Perhaps we take different photographs, or perhaps the gamut of my printer is exceptional . I agree that most colours in most prints lie with in sRGB - it'd be a pretty useless colour space were that not so. However, it's often been the few deeply saturated colours that have made my prints jump off the wall (and reflect my "I was there" memories), when what I could see on my ~sRGB monitor would suggest dullness. If I hadn't been confident that the images had more than the monitor was showing I'd never have printed.

FWIW the Lightroom 4 beta has a clever soft-proofing setup that shows, not only what colours in your image may be out of gamut on your chosen printer, but also which colours you are seeing in your image that are out of your monitor's gamut. IOW beware, what you see is not what you have or what you'll get! IMHO this is a huge step forward in soft proofing.

Tim

[Colin Southern]

However, it's often been the few deeply saturated colours that have made my prints jump off the wall (and reflect my "I was there" memories), when what I could see on my ~sRGB monitor would suggest dullness. If I hadn't been confident that the images had more than the monitor was showing I'd never have printed.

I think the important thing to remember is that working in wider spaces like Adobe RGB & Prophoto isn't a crime per se, but the wider the space, the greater the potential to go out of gamut without realising it if one doesn't know what they're doing. Couple that with the fact the many don't do their own prints - and most off the street shops can only handle sRGB - and for many, wide gamut spaces do more damage than good.

So if one wants to play safe, stick with sRGB - if one wants to take the training wheels off and feels confident ... go for it

[Boatman]

I think for simplicity's sake, I'm going to go back to aRGB. I've been using that for years without issues. I can always switch to Prophoto for the occasional hero shot if I need to. I have the raw images.

[Simon Garrett]

I think for simplicity's sake, I'm going to go back to aRGB. I've been using that for years without issues. I can always switch to Prophoto for the occasional hero shot if I need to. I have the raw images.

If you've got it to work with Adobe RGB (note: it's not aRGB) then fine.

Personally I don't think Adobe RGB is simpler! The problems that occur with ProPhoto RGB (note: ProPhoto not Photopro) will in general also occur with Adobe RGB - it's just that the errors with Adobe RGB are smaller so one might not always notice. I would argue that ProPhoto RGB is better, as it's absolutly blooming obvious when there's a colour space error!

If you use any colour space other than sRGB throughout, I strongly recommend using a colour-managed workflow, that is:

1. A properly calibrated and profiled monitor (done with a hardware device).
2. Colour-managed software that's set up correctly (e.g. Photoshop, Elements, Lightroom...)
3. You need to convert (not assign) to sRGB before hosting on the web (unless you know that the hosting software is fine with another colour space, and you know that all your target audience have colour-managed browsers - pretty unlikely, really).
4. If you print, you need to make sure that the printer also is colour-managed (correctly set profiles in print program or printer driver).

Perhaps you already use a colour-managed workflow. If you don't do all of these steps, then colours are always going to be a bit hit-and-miss. You can never be sure that you don't have an error somewhere that happens to be compensated (in your system) by an opposite error somewhere else. Colours may look right on your monitor or printer, but not on other monitors or other printers... And if you change a component (e.g. get a new monitor) the colours may suddenly look wrong.

Of course, this all applies with sRGB too, but most monitors and printers default to approximately sRGB, most print labs default to sRGB, and most other people's browsers and monitors will approximate to sRGB, so even without colour management everything will be very roughly right if you stick to sRGB. Very roughly.

[Colin Southern]

You need to convert (not assign) to sRGB before hosting on the web (unless you know that the hosting software is fine with another colour space, and you know that all your target audience have colour-managed browsers - pretty unlikely, really).

I hasten to add that even in the unlikely event of 100% of the target audience using a colour-managed browser in concert with a calibrated and profiled screen - they STILL probably won't see much more than sRGB would have shown them because chances are that's all the monitor is physically capable of. In other words they just took a HUGE gamble to accomplish - pretty much - nothing that they wouldn't have accomplished far far far far more safely by using sRGB on the web in the first place

(bangs head against wall! )

most monitors and printers default to approximately sRGB, most print labs default to sRGB, and most other people's browsers and monitors will approximate to sRGB, so even without colour management everything will be very roughly right if you stick to sRGB. Very roughly.

I might add too that I've found the biggest variation in monitors isn't the gamut - it's the levels - usually black and white points being off by a stop or more.