Re: Komura 2X multiplier

[Stephen <cameras@jetlink.net>]

seungmin@luxmail.luxcom.com wrote:
> 
>      Hi,
> 
>       I wonder if this subject has been discussed before.  I do have a
>      Komura 2X Multiplier for Leica screw mount with 90 to 210 viewfinder.
>      I have never tried this because I just got a screw mount lens.  I am
>      going to try it on my Canon rangefinder.  Before I put a film through
>      it, I would like some info on it.  Is it rangefinder coupled?  What is
>      the optic quality?  If it is so-so enough to degrade the quality of my
>      Leica lens, I would not even try it.  I am planning to use it with
>      90/4 Elmar.  Thanks in advance.
> 

Yes, it has been discussed rather extensively before.

It is RF coupled, and so can be used on the screw mount, or on the M
mount with the Leica M adapter.   

I have had good results with it,  Marc has had bad results with it.

The results will probably vary from lens to lens, as well as from
converter to converter.

ANY converter will degrade the image, even its only a very slight amount
due to the increased number of optical surfaces and so increased flare. 
Sometimes the degradation can be a lot, sometimes its rather minor.  For
instance, I've had good results with Nikon 2x converters on Nikon
lenses. 

I would suggest, however, that you take no one's word on any ANY len's
performance, and so test them to your own performance standards, NOT
someone else's.   What if the lens tester doesn't like the same type of
image you do?

Stephen Gandy