On Tuesday, October 25, 2005, at 12:30 PM, P. J. Alling wrote:
The likely reason for the longer mirror, aside from annoying people who want to use adapted lenses, is to insure that there won't be light fall off at the top of the finder when you're using longer lenses. If anyone is interested and has the cameras, they can see the effect clearly with a 600mm lens on the MX but the LX which has a longer mirror. It used to be a big deal, I'm surprised that Canon doesn't make point of mentioning it in their literature.
The mirror on the 5D is only about 1mm or so longer. The EOS-1Dv that I have does not suffer mirror cutoff with any lens I have put on it, not even 1,000mm. I don't think this is the reason for the lengthened mirror.
Bob
