I have a new 40D. I upgraded from a 350D and I can make comparisons between these two, but not a 400D. I have had the 40D for only about 3 weeks or so and I am still getting to know all the features.
With my 350D, I left it on ISO 100 almost all the time. If I shot at ISO 200, I noticed a pretty big drop in quality. WIth the 40D, ISO 200 is my standard ISO. This is mostly because I like Highlight Priority mode and this is not available with less than ISO 200. The ISO 200 quality is great, much better than 350D ISO 200. So far, I have not played much with higher ISO than this. I will soon.
The auto focus is also a big improvement over the 350D.
The custom controls C1, C2, and C3 I also like very much. You can use these to store any combination of camera settings. Then just turn the dial and you instantly are ready to go.
With my 350D, I left it on ISO 100 almost all the time. If I shot at ISO 200, I noticed a pretty big drop in quality. WIth the 40D, ISO 200 is my standard ISO. This is mostly because I like Highlight Priority mode and this is not available with less than ISO 200. The ISO 200 quality is great, much better than 350D ISO 200. So far, I have not played much with higher ISO than this. I will soon.
The auto focus is also a big improvement over the 350D.
The custom controls C1, C2, and C3 I also like very much. You can use these to store any combination of camera settings. Then just turn the dial and you instantly are ready to go.
