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 40D: Canon EF 50 mm F1.4 lens, Aperture Priority, ISO 100
JPEG Large/Fine, Manual WB, Default Parameters (Standard), Self-Timer (with MLU)
Canon EOS 40D
4.5 MB JPEG (3648 x 2736)
3.2 MB JPEG (3888 x 2592)
Although both cameras have ten million pixels the E-3's squarer sensor means it has a slight vertical resolution advantage (though we're only talking about 144 pixels here). That aside it's clear that once again there's very little difference here, though if pushed I'd say that the E-3 is capturing a slightly less processed-looking image On the other hand the E-3 may have improved highlight dynamic range compared to the E-510, but compared to the 40D it's still clipping pretty harshly.