[Leica] Enlarging lens recommendation

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

Dennis asked what the difference is between the older 50mm f2.8 El Nikor and the
new version.  two years ago I was looking for a new lens/enlarger combination
because I wanted to get into using variable contrast and color papers.  I had a
Focomat 1C without the filter drawer above the condenser (it was not the 1C
Color version), and I used it to test the Leica 50mm f4.5 Focotar and Focotar-2
lenses, the older and the new 50mm f2.8 El Nikors and the 50mm f2.8 Schneider
Componon.

The older Nikor has a rear element that is about 1/2 the diameter of the front
element, whereas the new (current) Nikor has a rear element that is about the
same size as the front element.  It is truly an f2.8 lens on a diffusion
enlarger, whereas the older one is not, but it is on a condenser enlarger.  On a
condenser enlarger the condenser focuses (i.e., condenses) the light onto the
rear element of the enlarging lens, so that the old Nikor is an f2.8 lens on a
condenser enlarger.  Anyway, the old Nikor is much better than the new Nikor on
the Focomat 1c in terms of contrast and color fringing at f5.6 and smaller
apertures.  I would not use the new one on the Focomat or any other condenser
enlarger.  I think the old Nikor was designed for condenser enlargers and the
new Nikor is designed for diffusion enlargers.  The Leica Focotar-2 is the best
of the lot listed above both in terms of resolution, contrast, color fringing
and performance at higher magnifications (larger prints) and at smaller
apertures (f11 & 16).  And it allows autofocusing on the Leica enlargers (even
the V35 can be modified for it).  The older Nikor and the older Focotar are
about the same in performance at f5.6 and f8, where you should use them, and can
be recommended without reservation (except that there is a better alternative in
the Focotar-2) for use on condenser enlargers, and probably diffusion enlargers.