[Leica] Which enlarger optic is the best, Focotar or Elmar?

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

In answer to the question, the Focotar is much better than the Elmar for
enlarging.  I compared the resolving power of the screw mount 50 Elmar red
scale lens to the first Focotar lens on my Focomat 1C enlarger.  The Elmar
was excellent in the center at f5.6 - f11, but the resolution on the far
edges and corners was not optimum until f 11, where overall performance was
excellent.  I was surprised by the excellent performance this lens provided;
however, it did not come close to the performance of my Focotar f 4.5 lens.
This lens was better at f 4.5  than the Elmar was at its optimum aperture of
f 11.  The Focotar shows best performance at f 5.6-8, where it is superb.  I
wish now that I had tested the two lenses at enlarging ratios of 16X and
above.  Maybe the Elmar would outperform the Focotar in this magnification
range.  Leica at one time recommended one of the 50 Summicron designs for
larger magnification ratios that 16X.  This lens was the first six element
Summicron, which was superseded by the current Summicron.  I have not read
in the Leica literature whether the current Summicron  is recommended for
large scale enlarging.

I enjoyed Horst's comments on the Elmar lenses.  Since the Elmar days, Leica
has issued three different 50mm f4.5 Focotar optical designs.  The first,
which I owned and used extensively, was a modified triplet (Tessar type)
with 5 elements, with the front element split with Leica air.  The next
formulation was a Schneider componon design.  It is known as the Focotar
with the large elements.  It is also an f 4.5 lens, but I suspect that it
was an f 4 lens that Leica diaphragmed down to f 4.5.  It is a Gauss variant
with five elements in four components similar to the configuration of the
40mm f 2.8 Focotar supplied with the V35 enlarger.  The last 50mm Focotar is
the Focotar-2, which features a six element, five component gauss optical
design.  It is optically superb at all magnification ratios up to 20X, and
perhaps beyond.  The first Focotar has the lens description on the front of
the diaphragm ring, whereas the last two designs have the descriptions on
the side of the lens barrel.  All of them take the 36mm slip/clamp on
filters.

Ferrel Anderson