If you don't need a lot of depth of field, set the ISO as low as you can, the aperture as open (low number) as you can, and then the fastest shutter speed you can get away with (tripod will help).
The specks are (probably) caused by a high ISO setting (like grainy film) or pixels being over-exposed due to long shutter time. You may not be able to avoid the problem, depending on the lighting conditions.
Saving in TIFF will eliminate the possibility of JPEG artifacts, but you'll have to empty the card more frequently.
If the specks are in the shadow areas, I'd try providing a little diffuse ambient light, like from across the room. This will "overexpose" your shadows a little; you can then darken them in post-processing. |
