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).
Olympus E-620: Olympus 50 mm F2.0 lens, Aperture Priority, ISO 100
JPEG Large/SHQ, Manual WB, Default Parameters (Standard), Self-Timer
5.9MB JPEG (4000 x 3000)
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. The E-620 can't quite beat the GH1 in terms of pixel level detail but it comes fairly close which is not that much of a surprise considering that the two camera's sensors are likely to be closely related from a technology point of view. Again, you'd have to produce very large prints to spot a difference.