[Leica] Re: Collapsible 50mm Summicron

[marcsmall at comcast.net (Marc James Small)]

A lot of our view of the first-generation 
Summicron lenses comes from aggressiving 
advertising by Leitz and by Leitz dealers between 
1954 and 1968.  Allow us to move beyond this and review the bidding.

The 2/5cm Summitar (1939 to 1954, only in LTM) is 
a really remarkable lens, and is a most 
satisfactory normal optick.  The one I own was 
the first Leitz lens I ever bought, and my family 
will have to peel it from my dead fingers after 
my passage to the hereafter, as I have no 
intention of getting rid of it any earlier!  I 
recognize that in hard testing on an optical 
bench, the CZJ 2/5cm Sonnar edges it out a bit on 
most parameters, but both the Summitar and Sonnar 
are quite nice lenses in use.

The 2/5cm collapsible Summicron was a marginal 
improvement in optical performance on the 
Summitar but was not the earth-shaking explosion 
of excellence Leitz claimed and the US photo 
press reported.  Leitz claimed that the 
collapsible Summicron was redesigned to 
accomodate the growing force of color photography 
but this is not really true:  the Summitar is 
perfectly capable of decent color imagery.  Leitz 
started to wake up to market economics with the 
collapsible Summicron by shifting almost all of 
their lenses to an E39 filter thread in place of 
the unique threads used on earlier lenses, such 
as the E36.4 thread used on the Summitar, a unique design.

The first versions of the collapsible Summicron 
contained radioactive rare-earth elements.  These 
proved to be too expensive for mass production 
and most of these lenses have non-radioactive 
glasses.  Leitz in those days had its own 
optical-glass lab but did not produce the glasses 
it used in lens production;  these were purchased 
through Schott, a Zeiss subsidiary and, thanks to 
the Versailles Treaty, the only optical glass 
manufactory in Germany at that time, even though 
Germany had renounced that Treaty two decades 
earlier.  Schott supplied and supplies many 
glasses but does not make them all:  many of the 
optical glasses listed in the Schott catalogue to 
this day come from Hoya in Japan and a few come 
from the USA;  in recent years, they have added 
glass suppliers from the former Warsaw Pact 
nations.  The significant point is that Schott 
controls the formula and works with its suppliers 
to meet the needs of customers.  All Hoya glasses 
are made, for instance, to meet Schott standards, 
and I believe that Schott is currently selling 
about 2/3 of Hoya's production, as Schott, unlike 
Zeiss and Leitz, will cut one heck of a deal.

The next version of the 2/5cm Summicron was the 
rigid lens, which later appeared with a revised 
mount as the DR ("Dual Range"), also known as the 
NF ("Near Focus").  This again tweaked the basic 
design to produce incremental improvements in 
performance.  The difference between a 
collapsible and rigid 2/5cm Summicron is really 
not great;  for that matter, the difference in 
performance between the Summitar and the rigid Summicron is not that great.

Those who do their own darkroom work can see the 
differences:  take a roll of slow-speed film and 
take identical shots with all three versions 
(Summitar, collapsible Summicron, rigid 
Summicron/DF) and then properly develop the film 
for minimum grain (TMY and Rodinal are not a 
recommended combination!).  Then play with 
cropped images to learn the differences.  I have 
done this, years back, and the superior 
performance of the rigid Summicron can only be 
noted with a lot of printing enlargement.  (I 
used a DR, only available in M BM, so I used 
adapters to fit the Summitar and collapsible Summicron to my M3).

I own all of these lenses:  the 2/5cm Summitar is 
on my IIIc, the 2/5cm collapsible Summicron is on 
my IIIg, and the 2/5cm DR Summicron is on my 
M3.  In the end, there really is not much of a 
difference between them, despite the claims of 
Lietz' advertising at the time and the claims of 
the clerks at Leitz' dealers back in the Longago.

The important point is to USE these lenses, as all are capable of great work.

Marc


msmall@aya.yale.edu
Cha robh b?s fir gun ghr?s fir!