Open letter to photographyblog.com (Review E-PL5; Nikon J2)

The point is to see how ISO 12800 behaves. Yes, there is going to be some very slight loss of detail at f/11 compared to f/5.6 due to diffraction. (Believe me, I know how this works -- not to be a dick and pull rank of a sort, but I'm a physicist.)

That loss of detail is very, very minor (at f/11), and detail that fine is going to be obliterated by the noise at ISO 12800 anyway. Yes, perhaps they should use something like ISO 12800 f/5.6 1/1000 instead of ISO 12800 f/11 1/250, but the use of f/11 doesn't invalidate the test, since that finest of fine detail that is softened by diffraction at f/11 isn't going to be visible in the first place.