Summar 5cm variations

[eastwestphoto]

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1 hour ago, wlaidlaw said:

All Summars being coated by E Leitz NY is not quite the whole story. Oude Delft in the Netherlands also offered a coating service for Leica lenses during the 1940's. My father's Summar was coated in the Netherlands in 1948, so I would assume by Oude Delft. 

Wilson

That's great, my next door neighbor was Milt Frier, head salesman for E. Leitz N.Y. , he told me in late 60's most all re-coating for uncoated Leica lenses was done by his agency or through his agency? I am very familiar with Olde Delft,  a Top notch optical firm. Leitz used a light blue coating, what shade is your coating? I tried a very recent Hoya MC filter on my Summar and it improved Color balance and contrast, than without it? Regards, Don

[eastwestphoto]

That is Good to know, I had been searching eBay with no luck for one of those early modified Summar's, I will start to look again. Regards, Don

[wlaidlaw]

1 hour ago, eastwestphoto said:

That's great, my next door neighbor was Milt Frier, head salesman for E. Leitz N.Y. , he told me in late 60's most all re-coating for uncoated Leica lenses was done by his agency or through his agency? I am very familiar with Olde Delft,  a Top notch optical firm. Leitz used a light blue coating, what shade is your coating? I tried a very recent Hoya MC filter on my Summar and it improved Color balance and contrast, than without it? Regards, Don

That was my father's Summar which sadly was stolen on his IIIa in 1967 on a trip to Madrid. From memory it was originally a brownish colour. I had it re-coated through Wallace Heaton in the mid 1960's, after I had tested the lens on an optical rig at university and found it sadly lacking, compared with more modern lenses. Virtually all the original 1948 coating had disappeared by that time. The new coating was bluish purple. The lens was considerably improved by its clean, de-haze, service and re-coating. 

Wilson

[willeica]

26 minutes ago, wlaidlaw said:

That was my father's Summar which sadly was stolen on his IIIa in 1967 on a trip to Madrid. From memory it was originally a brownish colour. I had it re-coated through Wallace Heaton in the mid 1960's, after I had tested the lens on an optical rig at university and found it sadly lacking, compared with more modern lenses. Virtually all the original 1948 coating had disappeared by that time. The new coating was bluish purple. The lens was considerably improved by its clean, de-haze, service and re-coating. 

 Wilson

For what it is worth, my 3 coated Summars are dark blue, light blue and a pink peachy colour respectively, probably done in 3 different establishments.

William

[eastwestphoto]

Do you have any 12 blade circular aperture coated 5cm Summar's? 

[jerzy]

vor 23 Stunden schrieb eastwestphoto:

Not true!  We are discussing whether the diaphragm makes a six sided hexagon or 12 blade circular diaphragm. Only the very early 5cm Summar does that!  It makes a BIG difference in the Bokeh of both Coated versions. Regards, Don

Don,

Post #44

Dennis Laney Leica book, the 1933 Summar 5cm has 12 blades, flat aperture.

 

Post #56

My personal copy is a Six blade No. 448582 coated also. That said there is a BIG difference between the Bokeh characteristics of the six blade Vs. the twelve blade. It is impossible to find a coated twelve blade Summar on planet Earth! Do you have a coated Six blade version? 

 

 

My reply in post #57 was in regard to the number of blades and if flat or curved.

 

Picture shows early rigid Summar (note f18 stop), curved aperture blades are where the arrow points.

 

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Is it possible to “convert” hexagonal Summar to circular? Yes, it is not so complicated but you would need a second Summar as a donor.

Summar has 6 blades of type A and 6 of type B. Type A produce hexagonal opening.

Except for the shape blades A and B are identical, same pins, same distance between pins

Replacing type A with type B (taken from donor Summar) will create perfect, circular opening.

And just for fun – the donor Summar.with 12 type A blades would have hexadecimal opening.

It is possible that f stops markings would not reflect reality when partially/fully closed – circular opening lets a bit more light through while hexadecimal a bit less than f stop mark indicates.,

Edited November 1, 2018 by jerzy

[wlaidlaw]

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Jerzy, 

Many thanks for your very clear explanation. Just to clarify one point, if you were to convert a Summar to round aperture using 12 type B blades, would the diaphragm be flat or bowed? I had always understood that the bowed diaphragm was an attempt to reduce the aperture shift that would be present with a flat diaphragm. Perhaps one of our resident Leica historians can answer: Was the bowed diaphragm patented by Leica? Also is the story that Zeiss were thereby prevented from using a bowed diaphragm on their Sonnar lenses just apocrypha? The 1954 Opton Sonnar 5cm/f1,5 on my Contax IIa, with a flat circular aperture diaphragm, does have some aperture shift but field curvature is probably a more significant problem. 

Wilson

[jerzy]

Wilson,

converted diaphragm would be curved/bowed, this is how they are formed now, both A and B. Why blades are bowed - not sure, maybe because the optical element above is curved, radius in which blades are bowed is approx the same as radius of the lens above. I am not aware if Leitz patented it, neither why Zeiss did not use it. Literure which I have does not say anything about it, sorry.

[eastwestphoto]

I believe the blades were bowed to keep the F:stop relationship of the inverse square law of light decreasing;  highly accurate,  when applied to a Double guass lens design. Strangely many manufactures used the double guass design, only Leitz bowed the aperture blades, that I know of? It was of course a very expensive design of blades to manufacture and by 1938 did NOT give Leitz a contract with the Reich military for lens manufacturing. Favored over Leitz; was Zeiss design on the Sonnar lens so much so,  that Zeiss was ordered to make their lenses with m39 thread mount also. Needless to say, Neither optical competitor was very happy and Leitz went back to the drawing boards and put out the 5cm Summitar in 1939. while that pleased Leitz, it ended the Summar 5cm designs manufacture and unique optical qualities. 

[eastwestphoto]

                                        While all these data comments and photos of the lenses are great and terrific , why did E. Leitz change the design of the Iris 1933 from round in shape,  to 12 blade Hexagonal in shape in 1934? It would seem a logical optical fact that a round iris produces a better out of Focus effect, called Bokeh these days. If both uncoated  lenses are shot equally with the same camera, same everything, the round iris is going to perform better; given that both lenses are clean with no defects? I have many 1930's lenses in different mounts in my collection, BUT none have a hexagonal iris in those years? So what Leitz did was radical for the time? Also the fact that its dome shaped to rise up towards the back of the third element in the double Gauss design is unique for the 1930's. Even if true calibration of F:stop markings was the goal, this is a unique very expensive design. Does anyone out their have a round iris rigid converted to collapsible that was coated? It would have a low serial #190xxx + or -. Regards, Don

[willeica]

 I don't think that bokeh was as highly prized in the 1930s as it is today, where it is quite overused on occasion. I am not sure why the hexagonal blades were used, but it could relate either to manufacturing convenience or to the nature of the collapsing mechanism for the lens. All of my collapsible Summars seem to have started out in life that way and to have had an hexagonal iris 'since birth'.

The nature of bokeh often has as much to with lighting or with the nature of the background as it has to do with iris shape. If you look at the two photos which I posted above on 30th October last, the one taken with an hexagonal iris has bokeh that is smoother (to my eyes) than that in the photo taken with a round iris. This has to do with the nature of the background and not the nature of the aperture. I believe that the collapsible Summar (I have 11 of them) provides lovely bokeh in out of focus areas. We should accept them for what they are now and no amount of post hoc investigation of why they were constructed the way that they are is going to change matters 85 or more years later.

William

[wlaidlaw]

I have been told it was to reduce aperture shift but I have no idea if this was correct. The other story was from the late 40's, when Leica did a full stock take of parts, which during the war, had been dispersed to many locations, farmers barns and so on, they found to their surprise, many thousand Summar hex diaphragms. So as not to waste them, later versions of the Summitar used this hex diaphragm in place of the earlier round aperture version. 

Wilson

[willeica]

4 minutes ago, wlaidlaw said:

I have been told it was to reduce aperture shift but I have no idea if this was correct. The other story was from the late 40's, when Leica did a full stock take of parts, which during the war, had been dispersed to many locations, farmers barns and so on, they found to their surprise, many thousand Summar hex diaphragms. So as not to waste them, later versions of the Summitar used this hex diaphragm in place of the earlier round aperture version. 

Wilson

Thanks Wilson. That is a more likely reason than any relating to bokeh, which was probably not even a word at that stage. You will glad to hear that the 1949 Summitar which came with my latest purchase from Westlicht (sharkskin IIIc - photo on another thread) is one with a round aperture like the early 1940s one also on view in that photo at the back. Both are coated and the main difference is that the later one stops down to f16 rather than f12.5 as on the earlier example.

William

[alan mcfall]

Perhaps not a variation, but for years I searched for a summar from the final lot. 503001-503600  Finally acquired it. Hex diaphragm.  Interesting that the serial is higher than some of the early Summitars, but still 1939 I expect.  A long 7 year run for the Summar.

 

 

 

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Edited December 16, 2018 by alan mcfall
wrong topic

[willeica]

Thanks Alan. Someone mentioned a Summar with a '5' on it to me recently , but my collecting mind was elsewhere with auctions at the time. This was, according to Thiele, from the last batch of Summars which came slightly after the first batch of Summitars. There is nothing unusual about this as Leica would have had parts in the factory and there still would have been a demand for the lens. As for the aperture design for the Summar, the Leica Archives may contain the original design drawings for the Summar and we may see these when the Archives/Museum are fully operational in 2020. Berek and his team would have been designing a lens that was collapsible, produced good image quality and was easy to manufacture. Bokeh, as we call it today, is a matter for taste and, in my view, the team at Leica produced a wonderful lens with the collapsible Summar. One of Leica's best in my view.

William

[eastwestphoto]

Agree I love the Bokeh on the Summar, some of my finest photos are taken with this lens on mirrorless Sony FF and APS-C chip size. I use a Mint Coated Summar, which took me a long time to find. Also a proper sunshade is a MUST! Used in the hands of a knowledgeable photog, the results are extremely satisfying. The trouble with modern designed lenses is there to perfect at removing aberrations, flare and ghosting etc. This has caused all photos to look too perfect. Photography is subjective to the viewer of course, but despite thousands of years that mankind has been drawing, impressionism became extremely popular and has lasted even to this day.

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[eastwestphoto]

On 12/15/2018 at 2:46 PM, willeica said:

Thanks Wilson. That is a more likely reason than any relating to bokeh, which was probably not even a word at that stage. You will glad to hear that the 1949 Summitar which came with my latest purchase from Westlicht (sharkskin IIIc - photo on another thread) is one with a round aperture like the early 1940s one also on view in that photo at the back. Both are coated and the main difference is that the later one stops down to f16 rather than f12.5 as on the earlier example.

William

I taken apart both the Summitar and the Summar and IMHO the iris assembly is not the same size. The Summitar is a much larger lens. BTW messing with the 12 blade hexagonal iris is ONLY for the very experienced. 

[samiba]

Am 17.12.2018 um 14:56 schrieb eastwestphoto:

Agree I love the Bokeh on the Summar, some of my finest photos are taken with this lens on mirrorless Sony FF and APS-C chip size. I use a Mint Coated Summar, which took me a long time to find. Also a proper sunshade is a MUST! Used in the hands of a knowledgeable photog, the results are extremely satisfying. The trouble with modern designed lenses is there to perfect at removing aberrations, flare and ghosting etc. This has caused all photos to look too perfect. Photography is subjective to the viewer of course, but despite thousands of years that mankind has been drawing, impressionism became extremely popular and has lasted even to this day.

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Such an amazing lens. I love it!

[willeica]

27 minutes ago, samiba said:

Such an amazing lens. I love it!

My favourite Leica lens without doubt.

William

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