Olympus E-PL2 High ISO RAW
Olympus E-PL2 High ISO RAW Image Quality
We've recently started looking at RAW files converted with dcraw, an excellent freeware raw converter. dcraw usually offers timely support for the latest cameras, but more importantly, it does not apply any noise-reduction, sharpening or other corrections such as geometric distortion correction to the output files. (We found that Adobe Camera Raw still applies some limited noise-reduction when its NR settings are set to zero, and it also applies other corrections depending on the make and model of the camera). There will always be differences between RAW converters, in terms of the sort of demosaicing algorithms they use (the processes by which they convert the separate Red, Green, and Blue data sets to an array of full-color RGB pixels), but dcraw seems to use a fairly generic algorithm that delivers good sharpness with relatively few artifacts, and can be counted on to not apply any noise reduction if you don't want it to.
Below are crops from Olympus E-PL2 high ISO RAW files compared to RAW files from other Micro Four-Thirds models: the Olympus E-PL1, Olympus E-P2 and the Panasonic GF2. All were converted with dcraw with no noise reduction or sharpening.
To our eyes, the new Olympus E-PL2 has very similar high ISO noise performance compared to the E-PL1 (if not slightly better), and both do slightly better than the E-P2. The Panasonic GF2 comes in last in this group, especially at higher ISOs.
Let's see how the Olympus E-PL2's high ISO RAW files compare to compact system cameras with APS-C sensors:
It's a little difficult to compare chroma noise because of the different color balance and saturation levels rendered by dcraw, but the Olympus E-PL2 actually does surprisingly well here compared to compact system cameras with APS-C sensors, especially considering its smaller photosites. (The 14.2-megapixel Sonys and 14.6-megapixel Samsung have more photosites, but the 12.3-megapixel E-PL2's pixel density is higher because the sensor area is smaller.)