Dave,
Thanks for correcting this!
Ulf Westerberg
>>Compare to the OM2000 which cannot handle
>> 600mm+ teles because of it's (too) small focus screen.
Dave Haynie wrote:
>It's not the size of the focusing glass, but rather, the mirror.
<snip>
>Telephoto cutoff is based on the angle of light rays leaving the lens
<toward the ultimate focal point, which is either the film plane or the
>glass. With a wide angle, the light from the lens is rapidly expanding
>from a (relative) point source toward the boundaries of the film plane.
>With a telephoto, the light leaving the lens tends toward parallel, the
>longer the lens. Once you get toward an infinite focal length (or close
>enough), the unformed image at the mirror plane is the same size as
>it'll be at the film plane. So with a too-small mirror, you only get
>part of that image.
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