Archived posting to the Leica Users Group, 2004/05/06

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Subject: [Leica] Macro Lenses: A Primer on Photars and Their Ilk
From: msmall at (Marc James Small)
Date: Thu May 6 16:07:57 2004
References: <> <002201c432fc$9a279810$87d86c18@ted> <>

At 05:34 PM 5/6/04 -0400, Max Weisenfeld wrote:
>I thought Stolze stops were fairly close to f/stops ... Stolze 5 between f/4
>and f/5.6, for example.  The markings on the Photar relate to much smaller
>openings, and much less light passage.  I have run some casual tests, and
>the difference seems to be in the range of 6 stops (metered at 1/30 @ f/2.8,
>shot at 8 seconds at f/(or whatever, stolze)8).
>I do not have access to Leica Manual 15th edition, so any help would be

Macro lenses have been made by a variety of manufacturers.  The most noted
are those from Zeiss (Mikrotars and Luminars), Leitz/Leica (Milars, Micro
Summars, and Photars), Nikon, Canon, and the Reichert Neupolars, along with
the Bausch & Lomb  Micro-Tessars.  These lenses are all modified microscope
objectives and provide great magnification with a flat field.  Their depth
of field is minute, so great care is required to bring the best out of them.

Almost all of these lenses are made in the standard microscope objective
mount, the so-called "Royal Screw" (it is actually the Royal Microscope
Society's Screw Mount as adopted at and 1869 conference in, I believe,
Paris or Brussels.)  This mount is 0.7965" (20.1mm) x 36 t.p.i. Whitworth
and is the standard world-wide.  Some of the larger Leitz/Leica and Zeiss
macro lenses, however, do require a special mount.  

These are generally marked not in conventional f/stops but in Stolze stops.
 These are geometric in progression and fit within the standard f/stop
system.  (See Wildi's work on the Hasselblad system for discussion;  my
copy is not at hand.)  Stolze developed the comprehensive scale for f/stops
which we use today when he was employed by Zeiss, though his initial scale
was that of the European stops soon rejected by Zeiss in favor of their own
International Scale which we use today.  I can dig up a lot more informtion
on this point if someone wishes to know the details!

RMS adapters are available readily from scientific supply houses (Edmund
Scientific, for instance, sells an RMS to T-Mount adapter).  I can use my
macro lenses with my Leica M (via the Bellows II or, in some cases,
directly on a Viso II/III) or on my Hasselblad 2000 FC/M.  These macro
lenses provide coverage to about 4"by 5" and Linhoff even markets an
adapter to fit them to their LF cameras.

If anyone wants to know more, I can provide a lot more information.  I own
a comprehensive (never say complete!) set of Luminar and Photar and
Mikrotar lenses and a number of Micro Summars, Milars, and Micro-Tessars.
I still lack the Repro Summar, part of the breed, but this has been low on
my priorities over the past several years.

There are also the oddball lenses, such as the Leitz 12cm Photar datring
from the 1920's and the later Zeiss S-Tessar, S-Biogon, S-Planar, and
S-Orthoplanar lenses.  Some of these guys are great:  the 4/60 S-Planar
makes a grand enlarging lens, for instance.

Marc  FAX:  +540/343-7315
Cha robh b?s fir gun ghr?s fir!

Replies: Reply from mail at (Karen Nakamura) ([Leica] FS: Leica CL, Alpex zoom finder, BOOWU, Nokton, Elmar, Jupiter, Rollei 35, etc.)
In reply to: Message from images at InfoAve.Net (Tina Manley) ([Leica] Ten years behind? I think not.)
Message from tedgrant at (Ted Grant) ([Leica] Ten years behind? I think so!.)
Message from msmall at (Marc James Small) ([Leica] Photar 25mm)
Message from max_weisenfeld at (Max Weisenfeld) ([Leica] Photar 25mm)