Please check these noise samples

[sasc]

Would you check this comparison page of my Pro 90 with my Casio for noise? Is my Pro 90 normal in this respect or something wrong. It shows this distinct blue and red blotching in all photos if enlarged or sharpened

Pro90 test pics (http://www.pbase.com/image/180841)

[MARobertson]

I'm not familiar with the Casio. I have the Pro90 and have found that ISO 50 gives the best/least noise picture. I'll have to examine some of my photos more closely to see if they do what yours did. I shot a picture of the full moon on July 4 (I haven't uploaded it anywhere) at ISO 50 (1/500 speed and f 4.0) and don't see any noise in the black sky. Have you tried your experiment with other colors? Wonder if that makes a difference.

[sasc]

Its most noticable in the blues. The darker greens will show some green and dark red or brown similarly. The darker the blue the more noticable it is. I will be curious to hear if your camera is the same or not. If not I would think something is wrong with mine.