[Leica] Focomat question

["Anderson, Ferrel E" <AndersonF@ria.army.mil>]

Q:  Is the autofocus designed for a particular lens?

A:  The autofocus is designed for the Leica 50mm f4.5 Focotar lenses, which are
manufactured to tight focal length tolerances.  Other brand 50 mm lenses have a
slightly different focal length, and do not work accurately with the autofocus
cam.  50mm Leica rangefinder lenses do work, however.  These would be the Elmars
and Summicrons.  I'm not sure about other Leica 50mm lenses such as the
Summitar, Summar, etc..  The screw mount versions work directly on the enlarger,
but the bayonet mount lenses require adapters.  The Nikor lenses are fine
lenses, and the earlier one, the one with a rear element significantly smaller
that the front element, works well on the Focomat.  The later Nikor has a rear
element the same size as the front element, and shows significant flare and
color fringing, but has excelllent resolution.  The earlier Nikor compares
favorably to the earlier Focotars, but the last Focotar, the Focotar-2 is still
one of the finest, if not the finest, enlarger lenses available.  It is a high
resolution lens, but really blows the competition away with its high contrast,
i.e.,  lack of color fringing and flare.  The speed of the Nikors is of no
practical advantage to me in focusing since I do not use heavy filtration and
use a grain focuser outside of the autofocus range of the Focomat.  In addition,
the f2.8 and f4 apertures do not show critical performance.  Both the Focotars
and Nikors perform near or at their maximum capability at f5.6 to f8.


Q:  How do other people manage VC on Focomat 1C?

A:  The same way as you if their Focomat model is not a Color version.  The
Focomat 1C Color models have a filter drawer above the condenser.  Bill is right
in advising that you can lift the top and place a filter on the top of the
condenser retainer, but it is a pain to keep doing this since the top is clumsy,
and accidents are probable.  Leica sold a below-the-lens filter holder, but this
is not available from them now.  Look for a used one.  Another option is to
adapt the below the lens red filter holder to hold VC filters.  Remove the red
filter from the retainer ring, and place the filter on top of the filter ring,
or retain the red filter, and attach a filter holder to the ring or ring column
on the other side of the red filter by some artifice.  I have checked the image
of a high resolution positive with a Peak Grain Magnifier with and without a VC
filter, and could see no difference in resolution of the finest lines.  You have
to use the filters that are designed for use below the lens though.