You're not wasting our time, that's what we're all here for - to debate and learn.
My thoughts are that you might be wasting your time.
If the image goes through Lightroom, it gets converted to ProPhoto RGB on the way. This conversion - any conversion - introduces a small amount of quantisation noise arising from the quantisation levels in the destination colour space, and simply the action of changing from one colour space to another. However, the image starts in 12 or 14 bits raw and already has other sources of noise probably at least as large as the 12 or 14 bit quantisation noise. The quantisation noise introduced by conversion to 16-bit ProPhoto RGB, even though greater than that of Beta RGB, is likely to be significantly lower than the SNR already in the image data, and so is unlikely to be perceptually discernable.
Converting then from ProPhoto RGB to Beta RGB is another conversion, introducing another processing step, and another (small) source of noise. Again, not likely to be significant, but the conversion can't undo any (small) quantisation noise introduced by the conversion to ProPhoto RGB introduced by Lightroom.
Further noise introduced by processing in Photoshop might be a bit lower if the processing is done in Beta RGB as compared to ProPhoto RGB, and I'd be interested to see any tests that show if this can be discerned in the image. Personally I doubt it's significant, but I'm open to being shown otherwise.
As others have said, I can't follow the logic of any benefit of Beta RGB with regard to colours out-of-gamut for real devices.
Hi Simon,
I hope I answered you in my post that overlapped with yours! It's unfortunate that I mentioned quantization errors because that's a complete red herring (a case of TMI!). Sure, there probably is some (no doubt insignificant) additional rounding-type errors when we use a larger working space and perhaps this is of interest to people like Bruce Lindbloom, but it isn't to me because I probably couldn't measure it and I for sure can't see it.
My post had to do with the potential problem of working in a very large working space from a gamut-mapping perspective. I think I demonstrated one aspect ... Perceptual mappings to the destination space ... above. Another issue is that it's very easy to push some colors OOG in any working space, but the larger the working space, the further you can push the colors OOG, and so the more the clipping that may occur on conversion to the destination.
Going to a smaller space like Beta RGB limits the problem but it doesn't make it go away.
I like to keep things contained and not to have to spend too much time watching Gamut Warnings, and then sometimes having to fix the OOG colors because they look bad on output. But that's just a preference ... if you prefer to do it the other way then fine, it's just as valid a way of working.
What I didn't mention is that my final working space is the print space. So I convert to Beta RGB first and ready the image for print; then I convert to the print space and do the final edits in that space. That way I can see the potential problems (I also turn gamut warning on for my monitor, so I know that I'm seeing what is going to go to the printer) and any edits I do are automatically constrained to the print space. I know you can achieve something similar with soft-proofing, but soft-proofing doesn't limit you, whereas the working space does. Again, this is just a question of preference.
I do appreciate your concern that I might be wasting my time, and perhaps you're right
. However, how much time does it take to convert an image from one working space to another? Once this step is in one's workflow the additional time taken is really insignificant (especially if you set the workspace in Photoshop to Beta RGB ... or whatever workspace you like) - and it would be completely insignificant if Lightroom allowed one to open the image in Photoshop using profiles other than sRGB, Adobe RGB or ProPhoto RGB.
Robert