Originally Posted by Boneappetit
I'll re phrase my question... Do over and under exposures from a camera are different from those I make in Camera RAW (converted to TIF)?
Boneappetit, try to look at the RetouchPro logo on the top of this page. OK, forget the logo and look at the grayscale. This grayscale has 10 different shades. Let's say you have a sensor which is able to capture only 5 shades (dynamic range 5). So you have to make a decision and set up your exposure somewhere to the middle but you will be missing 5 shades anyway. This is a single RAW shot. You can cheat and make new exposures from your RAW file but you will never get 10 shades anyway as they were not captured within the sensor. Or you can take two different RAW files, one for the "ligths" and one for the "blacks" and after getting them together you will get full HDR (high dynamic range) of 10 shades (5+5). Each scene is different and has different "dynamic range" - so sometimes you will be OK with one RAW file and sometimes you will need 3 or more RAW files as it was described above.