Olympus OM-D E-M5 Digital Camera Review
The motion rendition with the E-M5's video was superb, with great clarity, little ghosting, and without much visible artifacting. We did notice some trailing around our monochrome pinwheel, though, with the moire problem a pretty distracting element in our example motion video. Still, the camera is clearly capable of taking some sharp video, though its use of pixel binning seems to have created a bit of a moire animal anytime the camera isn't moving. More on how CamcorderInfo tests motion.
As we saw in the motion video, our sharpness test confirmed a pretty serious moire issue anytime a pattern of greater frequency than 400 LPPH is captured on video. The result is an ugly moire effect that causes these lines to blur together, resulting in either odd wavy patterns or discoloration, depending on the subject. Much of the detail was still there, however, with our test recording 700 LPPH of sharpness vertically and 600 LPPH horizontally in bright light (650 vertical/600 horizontal in low light at 60 lux). We believe the E-M5 is utilizing some sort of pixel binning or line skipping method of downsizing video from the 16-megapixel sensor to the HD signal, which is creating aliasing errors, resulting in moire. This is a common problem for DSLRs, but it does undo a bit what are some otherwise excellent videos from the E-M5. More on how CamcorderInfo tests video sharpness.
Low Light Sensitivity
While the Olympus E-M5's 16-megapixel sensor did well in most of our video tests, in the end it is still physically smaller than the APS-C sensors that its competitors have, hindering its low light sensitivity. Still, compared to its mirrorless competition, it didn't fare too poorly. With ISO on automatic (capped by the camera at ISO 3200), we found the E-M5 needed 18 lux of light to render an image that reached 50 IRE on a waveform monitor (about what would be acceptably bright when viewed on a television). This is actually right in line with the Sony Alpha NEX-7, which needed 17 lux to get a similar result.