Auteur: Dan Fromm
Date: 16-04-2005 17:46
Emmanuel, all of the Luminars except the 16/2.5 are triplets. I have in hand 25/3.5 and 40/4.5, have had another good 40/4.5, a badly-abused 16/2.5 and a terrible 100/6.3. My friend and neighbor Charlie Barringer has a good 100/6.3 that I have used.
I prefer my 100/6.3 Neupolar, made by C. Reichert Wien, now part of Leica Microscopy, to Charlie's 100/6.3 Luminar. The 100/6.3 Neupolar is indeed a reversed tessar. Its barrel is relatively long and narrow, and vignettes the image at low magnifications. For shooting 4x5 at 1:1 the Luminar would be the better choice. I shoot 2x3, so for me this is not a problem. As an aside, my 50/3.5 Neupolar is a triplet.
I recently bought, and even more recently worked out how to mount, a 90/6.3 CZJ Mikrotar. I haven't shot with it yet. Mine is a post-war coated lens engraved "M," not "Mikrotar." Marc Small, Charlie, and I have compared notes. It seems that early post-war Mikrotars were engraved Mikrotar, later ones M, and more recent still Mikrotar. In any case, my 90/6.3 is a reversed tessar.
If I were Stephane, I'd try the 150 G-Claron at 1:1 before thinking about other lenses. It is probably good enough. The big advantage of long macro lenses from microscope manufacturers is that they are optimised for use wide open. In my limited experience, differences in the quality of images recorded on film at apertures much below f/16 with "good" lenses are minimal. Most of us, I think, willingly give up some image quality in the plane of best focus to gain somewhat better sharpness in depth.
Best regards,
Dan
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