What's wrong with this Coll Cron?

B

bawang

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Any idea what is wrong with this lens? I am sure this is not a feature. There is no fungus or haze anywhere on the glass, only very light cleaning scratches on the front lens, negligible amount seen only with intense light from my torchlight.

Thanks.


4273727361_370f6b919a_b.jpg


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It sure looks like haze in there somewhere. It could also be an inner element out of position. The elements snap in very tightly with the Summicrons. I would be wary of the front groups being out of position IF you are sure that there is no internal haze.

You need to use a hood with these older lenses, but it should not cause this effect.
 
No. Is that why? I had a UV filter on it though and it was also clean.

I should be knocking my head on the wall if that is the only reason. I could have just rig a temporary DIY shade at that time.

Now I am not so certain that there isn't any internal haze. This has been CLA'd recently. I will check back when I get back home tonight. Any idea where I should look for the haze; center, edges?

Note to self: Get a hood!
 
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There is a big quality jump from a collapsible to DR/Rigid and later.

I disliked mine although it was clean, scratch free, and I used a shade. They lack contrast to around 5.6. I liked the similar Summitar better and I have two for various reasons. Also have a 50 2.8 original and late, DR/Rigid pair, and 1969 version 3, 50 3.5 Red Scale, and a Summarit. All are better than the collapsible was.
 
Any chance that their was condensation on the Filter? Condensation will evaporate from the edges and work inward. I see a lot of people wearing Jackets.

Collapsible Summicron at F2:

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Type I Rigid Summicron at F2:

picture.php
 
The haze is very local in the center.

So it can't be in the front of the lens and is unrelated to using a filter.

Maybe there was condensation on the rear, for example if you took the lens out of your warm jacket pocket, mounted it and took the photo.
 
To be that bad, as mentioned, I am sure the haze was wide and bad enough to be visible with naked eyes. I think I can rule haze out for now.

Never thought of condensation. But I think that might also be the reason. I recall using only that lens throughout the day. So condensation from changing lens can be ruled out. The weather was cold and most of the time the camera was in my jacket where the relative humidity is different than when shooting. I will definitely need to test this again when there's good light outside.

Looking at Brian's two pics, I don't see the big jump from Coll to Rigid. Perhaps I am not discerning enough.
 
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hmm

hmm

Optics are the same as the rigid, so contrast is the same. It's possible the one you had needed rebuilding ... I have great contrast, equal to any 50 cron. with my rebuilt one.

Ronald M said:
There is a big quality jump from a collapsible to DR/Rigid and later.

I disliked mine although it was clean, scratch free, and I used a shade. They lack contrast to around 5.6. I liked the similar Summitar better and I have two for various reasons. Also have a 50 2.8 original and late, DR/Rigid pair, and 1969 version 3, 50 3.5 Red Scale, and a Summarit. All are better than the collapsible was.
Click to expand...
 
I liked my collapsible (same as Paul's) very much. Decent contrast.

But optics are not the same as rigid/DR.

The rigid/DR has different dimensions from flange to front. To quote Marc James Small, the rigid/DR is a recomputation that was done by Mandler using a Zuse Z5 (thought you would like this, Brian :) )

For whoever is interested:

MJS said:
Subject: Computers and the Two Summicron Designs
From: Marc James Small <msmall@roanoke.infi.net>
Date: Wed, 03 Sep 1997 00:46:38 -0400

________________________________________
This is picking up a thread we had 'way back when, back in the Red Dog
Saloon Era, back when Eric Welch still was signed up (hmph!).

I came across a two-part paper written by Dr Walter Mandler, 'Leica Lenses and Early Computers', contained in the 1989 issues 22:1 and 22:2 of the LHSA journal, VIEWFINDER.

First, Dr Mandler confirms, as a couple of you LUG-nuts suggested, that the first computer at Wetzlar was a Zuse Z5 installed in 1952. Midland installed an IBM 604 calculating punch in 1954 which was replaced in 1957 by the use of an IBM 650 in the IBM office in Toronto. An Elliott 402F was installed at Wetzlar in 1958 to replace the Z5 and stayed in use until 1970; a second model went to Midland.

Mandler notes that the Zuse Z5 was used 'to redesign the Summicron 50mm f/2 for better performance at close-up distances. The result of these calculations was the second version of the Summicron 2/50, available both as rigid mount and dual range lens. (The second version has a longer distance from the first surface to film.)"

Thus, it is confirmed: there WAS a redesign of the Summicron between its first (collapsible) version and the rigid/DR version, and the latter two share the same design.

In addition to the 2/50 redesign, the Zuse was also used to design the 2.8/50 Elmar and 1.4/50 Summilux (this must be the first version of the Summilux, as the Zuse was replaced in 1958, before the reformulation to the current version.)

Marc
Click to expand...
 
Well with all due respect for these 1950 computers, I do think the Collapsible, when cleaned and rebuilt, has as good or better resolution, contrast, bokeh, microcontrast, glow, looks, compactness, and handling from 1m onwards compared with the DR or rigid.

Check my photos posted yesterday with Portra 800. Lens was rebuilt by DAG after being bought in the classifieds as "minty"

If the perception exists that the Collapsible is supposed to be a lesser lens, they will continue to be sold as "like new" or "perfect" when in fact, they need cleaning and/or rebuilding.
 
bawang said:
....snip.....

Looking at Brian's two pics, I don't see the big jump from Coll to Rigid. Perhaps I am not discerning enough.
Click to expand...

I agree, and I'm also not discerning enough - I'm glad I got a collapsible 'cron for hundreds less.
This also reminds me that I need to do some tests with it - need to finish off that roll I have in my CL.
 
Brian Sweeney said:
Any chance that their was condensation on the Filter? Condensation will evaporate from the edges and work inward. I see a lot of people wearing Jackets.
Click to expand...

I think that is an excellent guess, since it happened to me just the other day. Anyway, it's the first and easiest reason to eliminate.
 
Clarification

Clarification

I interpret below as the DR (NF) SOMNI in '56 as having a different computation. In other words, there is the rigid non DR, and then the DR. The DR (NF) is changed and has the hi-tech computation upgrades. The Rigid stayed the same to '68 or so.

Are there any known instances of different flange to front distances in the regular Cron 50 rigid SOSTA (11518) ? from the similar optic design in the collapsible SOOIC ?

ferider said:
I liked my collapsible (same as Paul's) very much. Decent contrast.

But optics are not the same as rigid/DR.

The rigid/DR has different dimensions from flange to front. To quote Marc James Small, the rigid/DR is a recomputation that was done by Mandler using a Zuse Z5 (thought you would like this, Brian :) )

For whoever is interested:
Click to expand...
 
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Rigid and DR are one and the same per Lager (and MJS above). Except for the focal length of the DR being hand-selected. You can put a DR head into a rigid mount but not necessarily vice versa.

Ted, I repeat, IMO, the collapsible is a good lens. And you are right about haze on some used lenses ...

I have a copy of Leica Viewfinder Vol. 39 / Nr. 1 / 2006 in PDF with more details on SOOIC-MS and SOSIC design. Email me if interested. In there (LEGENDARY LEICA LENSES, The 50mm f/2 “Rigid” Summicron by DICK GILCREAST), it says, among others:

DG said:
The rigid Summicron (SOOIC-MS, later SOSIC) was based on the design of the collapsible version, but the glass types were changed along with the curvatures and air spacing. Even the physical lengths of the two lenses are different. If one of the rigid Summicrons is placed alongside a collapsible version it will be seen that the surface of the front element in the newer lens is somewhat farther from the base of the lens than in the older. Although of the same focal length, the lens is physically longer. One design constraint in the older lens was that it was designed to be extra compact. It was 6mm shorter than the Summitar, and the new glass allowed a smaller front element which helped to minimize cutoff of the image in the viewfinder as well as making threaded filters more practical. Another constraint was the collapsible mount which limited size and placement of the rear elements. However the new lens would be designed for the viewfinder and larger bayonet lens flange of the M3 so it could be a little longer and larger without penalty. Image quality in the new lens was better in both large aperture work and close work. It was and still is a remarkable lens. Like most of Mandler’s lenses it has a very smooth tonal gradation and beautiful out-of focus transition (now called Bokeh) that defies description. It has many loyal proponents even today, 50 years later.
: : :
Leitz took advantage of the excellent closeup performance of the new Summicron by providing specialized closeup equipment. One was of course the well known Dual-Range Summicron (SOOIC-MN, later SOMNI).
: : :
The rigid Summicron underwent one revision during its lifetime, serial numbers placing it sometime in 1960 (Its code name by this time was SOSIC). The two versions have different knurling on the focussing rings, so they can be easily distinguished. Leica claims that the optical design itself was not changed, but the image quality of the later version was definitely different compared to the original version. The image at all apertures was more contrasty and “harder” in the later version. There was also perhaps a slight diminution of ultimate resolving power at the largest apertures, but the greater contrast made the images seem sharper because residual flare was reduced.
Click to expand...
 
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