Because a JPEG is ‘cooked’, the camera locks in all image parameters when the file is processed and modifying the image later on is well, less than optimal. I lent one of my camera’s to a friend and upon receiving it back, I forgot to make sure the camera was set back for RAW (as I am assuming he would have shot JPG). Anyway, I did a semi-important shoot with the D700 as a back-up body, switching over to it occasionally instead of changing lenses on the D3.
Upon reviewing the photographs, I then saw that photographs from the D700 were JPGs – oh no! So, the image parameter that I am complaining about in this regard is the image ‘clarity’ which is one of the most important RAW controls. Clarity controls mid-tone contrast which, when tuned in the RAW process, allows one to tighten up the image and make it appear sharper and conversely to produce a soft-focus glow effect on highlight regions of the image. This is only possible however, if the RAW image data is still accessible by the software. In a JPG, moving the clarity control is an absolute train wreck. Positive clarity will muddy-up the mid-tones and a negative adjustment just makes the image flat and drab-looking. A complete disaster. Reason # 782 for hating JPEGs.