Not much has changed over the original (three-year old) E-3 but there's a slight increase in pixel count to 12MP, a less aggressive AA filter, which should mean better micro-contrast (and according to Olympus is superior to both the EOS 7D and D300), a new image processor, and mono 720p 30fps HD movie clips. Fortunately, it has a stereo mic socket, and the 3-inch LCD is a big improvement too, with 921k dot resolution. For more information, please see the press release below.
