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 500D vs. Olympus E-620
Canon EOS 500D: Canon EF 50 mm F1.4 lens, Aperture Priority, ISO 100
JPEG Large/Fine, Manual WB, Default Parameters (Standard), Self-Timer (with MLU)
Olympus E-620: Olympus 50 mm F2.0 lens, Aperture Priority, ISO 100
JPEG Large/SHQ, Manual WB, Default Parameters (Standard), Self-Timer
Canon EOS 500D
4.8MB JPEG (4752 x 3168)
7.1 MB JPEG (4032 x 3024)
We've come to expect slightly softer images from Olympus but the latest generation of E-Series DSLRs (E-30 and now the E-620) has caught up quite a bit in terms of pixel level detail. If you look closely the E-620 can't beat the Canon 500D in this comparison, but it's not a million miles away and you'd have to produce very large prints to spot a difference. However, the Canon image is a little bit cleaner, and if you look very closely you'll find a few jagged lines and artifacts on the Olympus image (check the paper clips).
Buy the Canon EOS 500D (EOS Rebel T1i / EOS Kiss X3) from Amazon