Re: [Leica] Enlarging lens

["Henning J. Wulff" <henningw@archiphoto.com>]

Sometime in the early 80's I thought I might improve my images by upgrading
my old Focotar 50 from the early 60's. I bought (on approval) the
Focotar-2, and borrowed an Apo-Rodagon 50/2.8, and since I had a 40 Focotar
already, I had all the main lenses discussed here.

I read a test in an old camera magazine (I forget the name right now, but
it was the one with 'Darkroom' in it). I also forgot who did the test; it
might have been Ctein. In any case, he found that none of the 'Apo' lenses
he tested were actually apochromatically corrected except the 105/5.6
Nikkor....just a side note.

I also want to point out again that I had only one sample of each lens.

Tests were done on my Focomat Ic color, only with B&W film. My film of
choice at that time was FP4 developed in Perceptol 1:3.

My grain focusser is one of the original Micromegas.

When first looking at a negative (in the enlarger) through the Micromega, I
was dissapointed by the image that the Apo-Rodagon produced. It was
obviously unusable at 2.4, and not too good at f/4. At 5.6 it was quite
good, but nothing exceptional compared with my old Focotar.

It should also be noted that the original Focotar is actually a f/3.4 or so
lens that has been restricted from opening up to more than 4.5. The front
and rear elements are quite large, with the result that while the
Apo-Rodagon had a lot of vignetting at 2.8 and still quite a bit at f/4,
the Apo-Rodagon and the Focotar had about the same amount of light falloff
at 5.6. This meant that the only advantage the Apo-Rodagon had was a
brighter image for focussing at the center of the negative. At the edges
the lower contrast and resolution combined with the falloff made the
Apo-Rodagon less useful for focussing and judging the image than the
Focotar.

The Focotar-2 had minmally better performance than the Focotar when stopped
down a bit. Wide open it was not as useful as it had smaller lens elements
than the old Focotar, and thus had more light falloff.

The Focotar 40 had less even performance than the 50's. Center resolution
and contrast was very good; as good as the 50's, but performance fell off
more than in the 50's.

In prints all the characteristics noted through the Micromega were
confirmed. 8x10 and 16x20 enlargements were made; f/4 was used for the two
2.8 lenses and f/4.5 for the Focotars for the 8x10's, and f/8 for the
16x20's. I also made 8x10's at f/5.6 with the Focotars.

The Apo-Rodagon was about the same as the Focotar 40 at f/4, but the
Focotar had more light falloff. Both Focotar 50's were better, with the
older Focotar showing the least light falloff of any of the lenses on the
8x10's at f/4 or 4.5. I could not discern any difference in the prints made
with the two 50's, except for this light falloff. The same thing for the
prints made at 5.6, only now the Focotar-2 image showed only a very
slightly greater light falloff.

At 16x20 the images were very close, with the Focotar 40 image standing out
because of the greater light falloff. The Apo-Rodagon image was slightly
poorer than those of the Focotar 50's, with the edges being slightly poorer
still.

There was very little to choose between the images produced by the two
Focotar 50's. The -2 had slightly better contrast in the central areas of
the image, while the old Focotar was very slightly better at the edges,
both with respect to contrast and resolution.

My conclusion at that time was that

1) the Apo-Rodagon was not for me
2) the Focotar 40 was usefull for times when I ran out of room with the 50
3) although the Focotar-2 was very slightly better in some respects than
the old Focotar, on balance I liked the old Focotar better. So the
Focotar-2 went back.

Otherwise, I also have a Nikkor 80/5.6 (very nice performer with 645); a
105/5.6 Rodagon that I use for 6x6, 6x7 and 6x9 (also quite decent) and a
150 Componon-S for 6x12 and 4x5. All these lenses are quite good, but not
in the same league as the Focotars. I am considering a 150 Apo-Componon-HM.
Nobody around here has one as far as I know, so there is little chance I
will get one as I'm not spending the money before trying it out.

I used to have a Rodagon 150, but its elements headed off on their own. I
also had 2 other Rodenstock lenses which had separating elements, so I'm
not too anxious to buy another one. These were all bought around 1976
within a year or so. Most probably they have fixed the problem, but I'm
still unhappy with them. The enlarger lens test I conducted above was done
a long time before my Rodenstock lenses went bad, so was not influenced by
that.

   *            Henning J. Wulff
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