[Leica] 90/2.8 Elmarit-M as Macro

[leicaluvr at comcast.net (Tom Schofield)]

At a Leica Days It tried the macro adapter on 90's other than the Macro 
Elmar.  It does work on other 90's.  Since the 90 mounts upside down, you 
have to turn it over to see the f-stop, and there are no focus indications 
on the barrel of course.  My belief is that Leica does not give its blessing 
to use with other lenses is that it is off by the small differences between 
the true focal lengths of the various 90's (remember the little markings 
showing the correction from the indicated focal length to the true length on 
some lens barrels?), as well as marketing reasons.  Remember it's just an 
extension tube with a viewfinder correction, and the only optics are in the 
finder.  Since most stop down with macro, the minor focal length 
distinctions should not be a problem in practice.

Tom Schofield