Lately there's been some talk on this forum that 320 ISO would be an interesting ISO setting for the a900. Kind of a 'sweet spot' for the right exposure and noise. I compared 100 to 320 ISO and here are some screenshots of in-camera jpgs. It looks like 100 ISO shows more detail, saturation, better contrast and also less noise.
There's some purple fringe in the 320's that not visible in 100. Probably makes sense with the higher sensitivity, but it may be one more reason to stick with 100 ISO.
What are your thoughts? Why use 320 ISO?
320 is on the left, 100 right.