Originally posted by Robert S Donovan Shot last night. K10D, ISO 1600, 0.4 second, f/4.5, hand held:
I don't like the noise in the sky. I rarely shoot over ISO 800 for this reason.
FWIW, in that picture at that size, I don't see much noise per se - I see fairly extreme posterization, a totally different thing (google the term if you're not familiar). Partially due to JPEG compression, but partially just inherent in certain exposures and certain types of scenes (eg, underexposed skies).
I'm sure there's more noise visible at full size - unavoidable at ISO 1600. Although also relatively easy to control in PP, especially if you shoot RAW. But in any case, just wanted to make sure you weren't seeing the posterization and thinking that was noise.