Sony A550 High ISO/Noise Table
I wanted to do my own test of ISO and noise levels. It also seemed to me that the A550 noise pattern was finer grained with less chromatic noise when compared with the A100 and I wanted to test the effectivness of post processing noise reduction (I use Noiseware). The lens used was the Tamron 17-50mm zoomed to its maximum 50mm range, with natural light - no flash. Images were shot in RAW, imported to Photoshop ACR beta and basic brightness/contrast/color adjustments made, and then the image was saved as an 8-bit JPG. The following images were then taken from those JPGs.

ISO Full Image
resized to
1600x1065
100% Crop
of full image
Full Image
resized to
1600x1065
with Noise Reduction
100% Crop
of full image
with Noise Reduction
200 image image    
1600 image image image image
3200 image image image image
6400 image image image image
12800 image image image image

ISO 12800 Full Image resized to 600x400 with Noise Reduction: