ISO change in RAW files

[arde]

Hi all,

I wonder if when I manually change the ISO value of a RAW file viewed via the Canon FVU, this change has exactly the same effect -and will give EXACTLY the same result (so the primary RAW data will stay intact)- as if this picture had been taken with a different ISO setting in the first place.

I would expect that the ISO data in the EXIF file would also change to the 'new' ISO value if this was the case, but this does not seem to happen as far as I can see.

It seems like the aperture is actually the only thing I have to care about and almost all the other settings are a relic from the -analogue- past :-)

Best regards,

Armand

[hmhm]

No, the aperture, the shutter speed, and the ISO are all parameters that must be set correctly at the time you take the shot, you cannot _exactly_ recreate the effects of a different setting in post-processing. Raising the ISO is accomplished in-camera through increased amplification inside the sensor itself, the results are not identical to post-processing application of levels/curves or of the so-called "exposure compensation" applied in raw conversion.
-harry