We have tried to reduce these noise on DiMAGE A1/A2. However, the differences between pixels tend to be big when the image is recorded in a long exposure or high sensitivity mode. One part of noise cannot be removed and it tends to remain on the image as color dots because there are few signal levels in the condition to figure the image. The noise easily appears if the temperature of the camera (CCD) gets higher by the continuous operation. Please turn off the camera to cool down. Set the noise reduction to "On" in the night portrait and the aperture to open in P/A mode to keep the exposure time 1/2 to 2 seconds. We suppose the noise will not be noticeable. To reduce the heat on CCD, we recommend turning off the anti-shake and using the tripod.