This is old news but I intend to share it about how camera firmware upgrade can improve picture quality. Firmware actually is the software that running camera system, just like our computer requires operating system. Sometimes an error or defect can be fixed by upgrading to new firmware. It is common for DSLR because the system is complicated and users tend to discover new error that engineer never thought of. When there is a firmware upgrade we should thanks the manufacturer because their responsibility in correcting it. Of course they can just shut the door and release another better camera.
Here is Sony Alpha A700 picture comparison after firmware upgrade from v3 to v4. Left is v3 image and right is v4 image. It has improved the noise reduction logic and produce slightly cleaner image. These entire images are shot and applied low noise reduction from camera. I have to enlarge the picture up to 100% in order to find the minor changes. As a gear head sure I am happy about this improvement. The visible changes will be at ISO3200. But practically, how many will blow up my image to check every single details or compare the noise?
Image noise for me is less important because it is part of the digital sensor natural behavior. In old days anyone complain about ISO1600 film grainy? Many historical pictures were captured and still preserve until today. The picture is so harsh and lack of fine details but what is the matter? General photography is about capture moment and preserving memory.