[Patricia1066]

Above iso 1600 apparently the K-5 uses additional modifications to the raw file (including noise reduction) w/ raw capture, thus the comparison should not go above 1600, as you are losing resolution above iso 1600. (e.g., see Photographic Dynamic Range versus ISO Setting)

And presumably you used camera raw?

I can tell you I performed the same test going from iso 100 to iso 1600, and the images were identical after raising the exposure in pp w/ bridge/adobe camera raw in photoshop.

Yes, DNG and Fastrawviewer to adjust exposure.


I cropped into a series of shoots. One was in a sunny garden, flowers particularly were affected by ISO of 6400, while there was noise in the window panes at 1600 and above.


I used the wrong ISO above - I was comparing ISO 51200 and 640, not 6400.