Review (Summary): "We got our first batch of the Canon 40mm f/2.8 pancake lenses in today and, as with all new lenses, I had to run them through Imatest to establish our acceptable standards for the lens. Let me start by saying I had low expectations. I don't particularly like pancake lenses except on tiny cameras. They're usually compromises between size and image quality and I'm an image quality guy, mostly. ...
The 40mm f/2.8 lens is near peak sharpness wide open. The graph below shows 8 copies I tested at both f/2.8 and f/5.6. There's only a slight increase in sharpness (I'm not certain that difference would be visible in a photograph, it's within 5 SQF points.) That's wonderful, but ..."
