OK - here's one for the experts. If the light is poor, would you get better results underexposing by one or two stops with a RAW image and then correcting the exposure when converting or would it be better to increase the ISO
Increasing ISO... then use a noise-reduction program like NoiseNinja or Neatimage to clean up the noise since there are noise-profiles already available for that ISO.
If you underexpose and correct the exposure in RAW, the noise in the picture will be different from the noise profile for that ISO and thus noise-reduction software will not work as well.
Depends on the scene, and the behaviour of the camera files.
On a D60 I'd be more keen to underexpose and recover than if I were using my 1D.
If you underexpose and recover you're squishing up the dynamic range of the image - if there wasn't much in the scene perhaps that's not as much of a problem.
It also depends on how much adjustment is needed. If you're just scared to leave ISO200 then that's different to if you're already on ISO1600 and making the decision as to whether or not to bump to 3200 .....
I think I remember Chuck Westfall addressing this on RoB G's forums. The answer is use the high ISO setting as the noise handling routines in-camera will work better.
Also by under-exposing yoiu are are using the least sensitive part of the chip's dynamic range.
I've also heard that increasing ISO is preferred. On a 10D, however, this only works up to ISO 800. ISO 1600 and ISO 3200 are exactly equivalent to ISO 800 with EC of -1 and -2, respectively. The camera literally doubles or quadruples the ISO 800 values. FWIW, see this Usenet posting for reference.
Dave Baker wrote:
Depends on the scene, and the behaviour of the camera files.
On a D60 I'd be more keen to underexpose and recover than if I were using my 1D.
If you underexpose and recover you're squishing up the dynamic range of the image - if there wasn't much in the scene perhaps that's not as much of a problem.
It also depends on how much adjustment is needed. If you're just scared to leave ISO200 then that's different to if you're already on ISO1600 and making the decision as to whether or not to bump to 3200 .....
I agree with Dave, I have the 1D & D60 also. The D60 does well underexposing and pushing later in PS; whereas, the 1D does not seem to like lots of PS manipulation. I guess it depends on the camera.
Steve
I believe if push via ISO setting, the CMOS sensor gain (sensitivity) increases (along with system noise), you lose a bit in signal to noise ratio. If push via under-exposure, you lose dynamic range. For 1 stop underexpose, you turned a 12 bit sensor in the 10D into a 11 bit but gained a lttle bit in lower noise.
