Pano, Could you please explain a little further for me. I didn't think that the exposure offset was ISO dependent. What correction should I apply to the exposure slider in CR to offset the program's offset for a IDS III, and does it have to vary with ISO?
It is not only ISO dependent. It is a general compensation for whatever. For example if HTP is ON, then +1 EV is applied (it adds to the adjustment, i.e. for the 1Ds3 it will be +1.35 EV); however, you have no reason to use HTP, that's for JPEG.
The adjustment (without HTP) is +0.35 EV for all ISOs. However, there is no ISO 50 in the 1Ds3 (nor in any other modern Canon DSLR). ISO 50 is simply an overexposed ISO 100. DPP too compensates for that by a negative "brightness" adjustment, and ACR substracts 1 EV from the otherwise determined adjustment.
For example most MFDBs don't have ISO steps higher than 100. Anything higher means simply automatically adjusting the intensity in post-processing; that too occurs through BaselineExposure.
Note, that this name, BaselineExposure, is not an ACR issue. ACR is doing that automatically; however, if you convert the native raw file in DNG format, the DNG converter records this information as metadata for the later raw processing, so that the DNG image can be processed based solemnly on the DNG metadata, i.e. without having to know the specialties of the camera, like HTP.
