Compared to...

Studio scene comparison (higher sensitivity)

As well as shooting our studio test scene at each camera's lowest sensitivity we also shot it at ISO 800 and 1600. Canon's superior image processing and perhaps milder noise reduction maintains more detail at ISO 800 (although not by a large margin), at ISO 1600 things are more balanced with certainly more noticeable chroma noise than from the Nikon D80.

ISO 800

Canon EOS 400D Nikon D80 (Normal NR)
Sony DSLR-A100 Canon EOS 350D (8 MP)

ISO 1600

Canon EOS 400D Nikon D80 (Normal NR)
Sony DSLR-A100 Canon EOS 350D (8 MP)