Hi--

>> errr..., David...;-)

>Boy its hard to keep track! But then I confuse so easily ;-)

Uh, meeee, toooo....;-)

>Again, for clarity
>a 50mm lens with the previously mentioned 11 filter becomes a 25mm??? I do not
>wish to confuse with minimum focus distance, which DOES change with tubes and
>filters.
Jack Daynes <"jackd1[NOSPAM]"@san.rr.com>

Yes - but good luck using it at infinity and at "f1"....;-)
The maximum focus distance is as fixed as if it were a 25mm
lens on a 25mm tube - and the "f1" lens with an effective
aperture of f2 on the 11 "tube" is as soft as one would expect
wide open...