The D80 comes with a High Noise reduction function, I haven't messed with it much but I have some questions. 1. Are you better of using this than say reducing the noise in photoshop? 2. The stetting are normal, low and high. Would normal be the default setting? 3. If shooting at IS0 1600 and having the noise reduction set to high, would the camera detect if I switched to IS0 100? and not try to reduce the noise at 100? Or would it make a shot taken at 100 look soft and muddy? 4. Sort of related to my last question, how does the noise reduction setting react with the auto iso settings? Can the camera see the difference between 100-1600 and react accordingly?