This is our standard studio scene comparison shot taken from exactly the same tripod position. Lighting: daylight simulation, >98% CRI. Crops are 100%. Ambient temperature was approximately 22°C (~72°F).
Canon EOS 400D / Rebel XTi vs. Sony Alpha DSLR-A100
Canon EOS 400D: Canon EF 50 mm F1.4 lens, Aperture Priority, ISO 100
JPEG Large/Fine, Manual WB, Default Parameters (Standard PS), Self-Timer (+MLU)
Sony DSLR-A100: Minolta 50 mm F1.4 lens, Aperture Priority, ISO 100
JPEG Large/Fine, Manual WB, Default Parameters (Standard), Self-Timer
Canon EOS 400D
3,351 KB (3888 x 2592)
2,868 KB JPEG (3872 x 2592)
Again any differences in this comparison will be down to different image processing, primarily better / stronger sharpening from Canon. Sony also don't appear to be as good as Canon at removing 'false color' (moire) which can be seen on the first crop in the series.
Buy the Canon EOS 400D (EOS Digital Rebel XTi / EOS Kiss Digital X) from Amazon