PJ Jacobowitz’s review of the Olympus PEN E-P1 has the following verdict on its image quality:
Images produced by the E-P1’s 12.3 megapixel sensor are spectacular. In PCMag Labs, I use a testing suite called Imatest, which offers objective tests that gauge image quality. The results showed that the images produced by the E-P1 are extraordinarily sharp, competitive with or even better than most SLR’s in its price range. Noise was undetectable at ISO 100-1600, which is also better than more expensive cameras.