[Steve]

Originally Posted by Markulous

LOL, P-E! Yeah, I'm impressed by the D200 for sure!

Interesting that the 30D has less noise at high ISOs as I thought the Nikon was pretty good. Having said that was very disappointed by the de-noising on the 350D I have borrowed - instant nutella across the whole image despite the correction being in just the one colour channel (my Sigma's got the detail in depth to not nutella). Maybe it's because the image is already interpolated with Bayer sensors?

I am not going to get into an Canon/Nikon argument here but I can assure you that there is a significant difference between the sensor in the 350D and the 30D but even more so between the Canon 30D and Nikon D200 where noise is concerned. In my opinion neither are bad (and your comment about de-noising a 350D pic is a little worrying anyway) but there is definitely more noise visible in a D200 shot taken at a higher iso than the Canon 30D shot at the same.

Bearing that in mind perhaps you would be better staying with the Sigma that you know and love. At least you'll only be upset when you don't have the right lens for the job rather than with every single shot at the end of the day