Originally Posted by photog 
"I have found my red rose pictures taken under a light cloud cover are over saturated in red. Other colours seem OK."
You don't identify the camera but I had the same problem with the K10 until I used the highest colour space abailable in Bridge then down sampled the image to sRGB or Adobe RGB 1998 as needed. The latger colour space will pritect your reds and so on and Adobe Bridge can save in a lower colour space without losing the saturation in the reds.
Ron McDermott
I assume you mean *converted* to either sRGB or AdobeRGB. *Down-sampling* is what you do to change the resolution.
The fact is, all things being equal, if you first render the raw file into a wide gamut space such as ProPhotoRGB to prevent clipping and then convert to one of the smaller standard working spaces, clipping will still occur. The reason is that all of the standard Adobe-supplied RGB working space profiles, and a few of their CMYK ones as well, will only perform a *relative colorimetric* conversion EVEN IF YOU CHOSE PERCEPTUAL RENDERING in the conversion dialogue. Bottom line, rendering into ProPhoto and then converting to sRGB is really no different than rendering into sRGB in the first place...the amount of color clipping will be the same.
There's really only a couple of options for preventing clipping:
1) Once you've rendered into a wide gamut space such as ProPhotoRGB, you use Photoshop to then reduce saturation to bring the saturated colors within the gamut of the smaller gamut space that you intend to convert to to. You can use the gamut warning and soft-proofing in Photoshop as a guide to tell you when you have the colors sufficiently corrected so they do not clip when converting to the smaller gamut destination profile.
2) Once rendered into ProPhotoRGB, you convert to a destination profile that is a *LUT-based* profile, not a matrix-based profile (all of the standard RGB "working space" profiles supplied by Adobe are matrix-based profiles and do not have a perceptual rendering table). A LUT-based profile will generally have both colorimetric and perceptual rendering tables so that when you choose the perceptual intent, you'll get a true perceptual rendering that will normally prevent clipping (but not always). GENERALLY SPEAKING most printer/output profiles, both RGB and CMYK, are LUT-based profiles.
The only way to know POSITIVELY whether a particular profile is a matrix or LUT-based profile is to use a utility such as ColorThink by Chromix or perhaps the ColorSync utility.
Regards,
Terry Wyse