Archived posting to the Leica Users Group, 2004/12/12

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Subject: [Leica] The only Leica I ever sold -- survey time
From: sethrosner at direcway.com (Seth Rosner)
Date: Sun Dec 12 07:18:40 2004
References: <BDE214AF.407A7%joseph@yao.com>

Joseph, I beg most respectfully to differ with you on the contrast of the 
Kern 50/1, 9 Macro-Switar. You are quite right on its resolution, very 
comparable to the DR/Rigid Summicron. But its contrast cannot properly be 
called low. Unless one is speaking strictly of the lens wide open and at the 
far edge (18mm off-axis). At worst, if one were speaking generally, i.e. of 
the lens at various apretures and various points on the film plane, it is a 
medium contrast lens. Fuller explanation follows for those interested.

While I agree with those who say "take photographs, look at the results and 
THEN decide if you like a lens" -out of curiosity last year I took five 
lenses to Cambridge Mass. to a company called Optikos Corporation that does 
optical design and engineering and has state-of-the-art test equipment.

My interest was mainly to see how the 35/2,8 Summaron fared when compared 
with the first generation 8-element and the pre-ASPH 35/2 Summicrons. I have 
written an article on the results for these three lenses for LHSA's 
VIEWFINDER magazine that should appear in the next issue.

I also took along and had Optikos test my 50/2 Rigid Summicron and Alpa Kern 
50/1,9 Macro-Switar. While the contrast of both of these lenses at full 
aperture is lower than the current generation of Leica lenses, especially at 
the far edge (18mm off-axis), when stopped down to the medium apertures at 
which I usually shoot, the contrast of both is very, very close to that of 
the current 50/2 Summicron that Erwin has so often so praised. In fact, at 
medium apertures and some points on the image plane, both the DR/Rigid and 
the Switar slightly exceed the contrast of the current 50 Summicron!

Incidentally, the 50/1,9 Macro-Switar was recomputed from its predecessor 
50/1,8 in 1968 and my information is that it was indeed multi-coated.

Amazing how much "information" is out there and how it becomes gospel. More 
astonishing still is the outstanding performance of this 36-year-old design 
and of my old favorite, the DR/Rigid that in two years will be celebrating 
its 50th birthday!

My 36 year-old nephew was straight digital until 18 months ago and has now 
gotten into Leicas. First bought an M6TTL with a 35/1,4 ASPH and a Noctilux. 
Found the Nocti too heavy and bulky and sold it a few months ago for a new 
50/1,4 Summilux ASPH that he loves and a new MP. I spoke with him yesterday 
to learn that a couple of weeks ago he bought a clean Dual-range from Stan 
Tamarkin and is astonished at the images he is producing.

Bests,

Seth          LaK 9

----- Original Message ----- 
From: "Joseph Yao" <joseph@yao.com>
To: <lug@leica-users.org>
Sent: Sunday, December 12, 2004 2:30 AM
Subject: Re: [Leica] The only Leica I ever sold -- survey time


> The lens is a Kern Macro Switar 50/1.9 from my Alpa SLR.  I got an 
> Alpa-LTM
> adapter from Retina House in Tokyo.  Add one LTM-M adapter the lens goes
> onto any M camera.
>
> This lens has amazing resolving power, but the contrast is low due to the
> single coating.
>
> Joseph
>
>
> on 11/12/04 11:24 pm, Slobodan Dimitrov at s.dimitrov@charter.net wrote:
>
>> Isn't that Alpa lens one of Tom's hybrids?
>> S. Dimitrov
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information
> 



In reply to: Message from joseph at yao.com (Joseph Yao) ([Leica] The only Leica I ever sold -- survey time)