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Kingslake seems to be right. It was generally known already before 1900 that lenses that had spontaneously acquired a "blooming" on their surfaces had superior transmission and flare characteristics. Various experiments were done with different processes and substances.

 

This was indeed a big issue. A Planar type double-Gauss lens has at a minimum eight air-glass surfaces. Every one of them increased flare and internal reflections logarithmically. This was essentially the reason behind the Sonnar lenses, which are really cemented triplets, with six air-glass surfaces, just like a Cooke triplet! This worked, but restricted the degrees of freedom available to the designer. You had to sacrifice something; in the Sonnar case, it was largely planeity of field. Coating made it possible to break out of this straitjacket – and the double-Gauss design came to dominate the scene for nearly half a century.

 

Of course the German authorities failed in their attempt to restrict the knowledge. You can't suppress the knowledge of natural laws, and the correct answer was quite close at hand, as proven by Kodak's early trials with calcium fluoride. Higher temperatures, a harder vacuum and extreme cleanliness were the answers to the problems. In other words, straightforward process development.

 

Similarly, there was no 'secret of the atomic bomb' as the hysterical press (and Joe McCarthy) would have it. Not since that Christmas Day 1939 in the snowy woods outside Kungälv, Sweden, when Lise Meitner explained to her nephew Otto Frisch what Otto Hahn had done, but not understood – split the atom. The genie was out of the bottle. (And Heisenberg and others in Germany came to understand it too, but deemed the purely technological challenge to be too great.)

 

The old man with a kinky, but long memory

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Similarly, there was no 'secret of the atomic bomb' as the hysterical press (and Joe McCarthy) would have it. Not since that Christmas Day 1939 in the snowy woods outside Kungälv, Sweden, when Lise Meitner explained to her nephew Otto Frisch what Otto Hahn had done, but not understood – split the atom. The genie was out of the bottle. (And Heisenberg and others in Germany came to understand it too, but deemed the purely technological challenge to be too great.)

 

The old man with a kinky, but long memory

The real history is writen in Jonas Jonasson book :The Hundred-Year-Old Man Who Climbed Out the Window and Disappeared , which I just finnish to read :cool:

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  • 8 years later...
On 7/24/2012 at 4:31 PM, jc_braconi said:

This 1954 issued one is in feet scale s/n 1 159 xxx :

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My copy is in feet scale and in the 940xxx serial range. I love it for its copious character. A really unique portrait and art lens.

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  • 4 years later...

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I have been searching for information on the Summarex lens and came across this post from a few years ago.

Recently I purchased a set of 4 Summarex filters in their original boxes, although I don't actually own a Summarex lens.

I can also show an article on Leitz lens coatings that I read recently and was very interesting.

Regards

Alan

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  • 2 weeks later...

I am sure everyone in this thread has seen the early (593008) Summarex on eBay that's been there for a while. I badly want a black Summarex; however, to me, it seems to be something to pass up because of the condition issues and the price. Even when I spoke with master repairman Youxin Ye, he said it was definitely collectible but he could do nothing about the fungus and separation and it would just make a homely display piece.

I'd welcome reading the opinions of others who have been in the situation where they faced the dilemma of rarity vs. condition vs. price...

Dave (seekwhence)

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47 minutes ago, seekwhence said:

I am sure everyone in this thread has seen the early (593008) Summarex on eBay that's been there for a while. I badly want a black Summarex; however, to me, it seems to be something to pass up because of the condition issues and the price. Even when I spoke with master repairman Youxin Ye, he said it was definitely collectible but he could do nothing about the fungus and separation and it would just make a homely display piece.

I'd welcome reading the opinions of others who have been in the situation where they faced the dilemma of rarity vs. condition vs. price...

Dave (seekwhence)

Have you asked Don from DAG?

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If you want a better one... 😗 https://www.ebay.it/itm/286099650097

For such items any advice is someway peddling.... a black Summarex with that number is a high level collectible and full originality is more important than conditions : the only warning I really find is the mood of the description ("king of Bokeh" 😁 ,"If you want it cheaper i Will lower the price...") which arises some issue about seriosity of the seller.

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