Here we go. Today I started out to capture the famous yellow flower (at sunny daylight); colors even fall out-of-adobeRGB. In fact, I made two shots: sRGB JPEG and Raw. The Raw file was processed at camera-default settings to ProPhotoRGB, 16 bit. The only manipulation involved (by purpose) was that I set all sharpening to zero; in-camera as well as in ACR.
Both files were soft-proofed to an Epson premium glossy profile. The paper doesn’t really matter, however, the scenario is clearer because the sRGB JPEG file is completely in-gamut now. Whereas the ProPhotoRGB file shows many many out-of-gamut marks with regard to the printer profile.
Surprisingly, the sRGB JPEG file shows much more details (at 200% magnification), whereas the ProPhotoRGB file shows posterization. Changing the SoftProof from RelCol to Perceptual helps, but not perfectly.
How can this be? It seems to me that the in-camera conversion & gamut compression to sRGB is somehow realized by a proprietary perceptual algorithm. No / less channel clipping, unlike RelCol. Remember, if the color engine supports this, it’s even possible between matrix spaces (afaik). If someone knows more, please post. Finally, saturation is sacrificed while details are maintained.
Also, it’s obvious for me that the Perceptual intent with the printer profile does not differ enough from RelCol to deal with such remote out-of-gamut colors from ProPhoto RGB.
This does not claim to be a scientific test. Equipment or whatever may play a role. Others may get different results or see things differently. A round-robin test could help. Also I desisted from any image editing, which of course requires only basic PS skills to realize a perceptual de-saturation by hand.
Do I like the results – no.
Do I want to go back to sRGB JPEG – no.
Am I missing something here – can’t exclude!
Do I go on holiday now – yes, soon .