Nicht immer nur Kaviar ... (English Version)

[PG Black nickel]

Advertisement (gone after registration)

Yes,

It is a camera for fighter planes. It is a French camera of mark OPL (Foca) model 1923. It was used for the instruction of the pilots for the shootings with the machine-gun with which it was coupled in order to check on the prints the accuracy of the shootings. 
It is in a wooden box adapted with the tools and the spare parts.
The lens is an OPL 170 mm F5. 120 mm Kodak film. 15 frames.
It is quite imposing it measures about 40 cm and weighs about 5 kilos....

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[thomas_schertel]

Two Tenax I and Tenax II

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

yours sincerely
Thomas

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[pgk]

Another Grubb lens. This one dates probably from the 1890s but appears to be of 1850s design. It would have been an old design by then and its performance would not have been up to the current lenses which used Jena glass. So why I wonder was such a lens manufactured so much later on. The 40 year production cycle is impressive but somewhat odd.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[romanus53]

Sorry if I had shown this here before but the French camera for fighters reminds me to this one: gyroscopic gunsight recorder

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

the cables and plug are of course not original but I wanted to try it out after I fixed the mechanics. Finally I sold it to someone restoring a Mosquito cockpit where it belongs.

Edited December 28, 2022 by romanus53

[wlaidlaw]

1 hour ago, pgk said:

Another Grubb lens. This one dates probably from the 1890s but appears to be of 1850s design. It would have been an old design by then and its performance would not have been up to the current lenses which used Jena glass. So why I wonder was such a lens manufactured so much later on. The 40 year production cycle is impressive but somewhat odd.

Paul, Remind me how long the 50mm Summicron M has been in production, with versions IV and V only differing by the built in lens hood. I think it is 1979 to date which is 43 years, so nothing really odd about the Grubb lens longevity of production. Admittedly Leica now offers the Summicron in the APO version but at a very steep uplift in price. 

Wilson

[pgk]

6 minutes ago, wlaidlaw said:

Paul, Remind me how long the 50mm Summicron M has been in production .....

Indeed, but the Summicron was 'fit for purpose' since its original design and still is. The Grubb Patent lens was a simple cemented doublet and by the 1880s there were numerous optical makers looking into the increasingly popoular and potetially lucrative photographic marke,t and many moved into it - Wray, Beck, Dollond, Swift - even if some then found it too hard and competitive and gave up. To illustrate how much effort needed to be put in, Wryy had a machine dedicated just to producing aperture diaphragm leaves. Lens designs were becoming more sophisticated with the mathematics behind them slowly becoming clearer. Against such a backdrop, producing a lens from a very old design seems a little odd, good as it had been in its day. I suspect that there is a lot more to it than meets the eye though. The history of commercial lens success is a difficult and complicate one no doubt.

[nitroplait]

Advertisement (gone after registration)

16 hours ago, wlaidlaw said:

Paul, Remind me how long the 50mm Summicron M has been in production, with versions IV and V only differing by the built in lens hood. I think it is 1979 to date which is 43 years, so nothing really odd about the Grubb lens longevity of production. Admittedly Leica now offers the Summicron in the APO version but at a very steep uplift in price. 

Wilson

Apropos current lenses with long production runs.

The lovely Nikkor 28mm 2.8 AiS was introduced in 1981 and I just checked to confirm that it is still unchanged in the Nikon product catalogue. Quite an achievement.

Of course, If you look only at optical design, the Nikkor 50mm 1.8 design can probably be traced even further back, but with many different barrel and coating variations over the years.

[wlaidlaw]

Thinking of cemented doublets, the Leica Visoflex 560mm f5.6 Telyt lens, sold as late as 1973, was just a simple cemented doublet and it showed. Definition at anything other than the centre of the image was indifferent and only adequate in the centre. Certainly compared with my Zeiss 600mm f8 lens or Leica 500mm MR-Telyt, it was a quite poor performer and of course, huge. 

Wilson

[zeitz]

1 hour ago, wlaidlaw said:

a simple cemented doublet

The cemented doublet of crown and flint glass elements is the first optical formula beyond a simple magnifying glass.  It dates back to telescopes, way beyond the invention of photography.  One of its principle monochrome optical faults is field curvature; since the design is an achromat, there is also significant chromatic aberration.  Field curvature was helped by limiting the max aperture to f6.8 on the subsequent 560mm lens.  The 800mm f6.3 Telyt S achieved a flat field and apochromat performance using a Steinheil cemented triplet with exotic glass elements.

[pgk]

2 hours ago, nitroplait said:

Apropos current lenses with long production runs.

The Nion 35mm f/2.5 RF lens started life in 1952 and remained in production until 2001 in the guise of the 'standard' Nikonos lens. A near 50 year production run (actually they were still available 'new' off the shelf for several years after 2001).

The Dallmeyer 3B lens is sort of still available and originated in 1866 (https://www.eckop.com/completed-projects/historical-reproduction/) but this is perhaps pushing it.

[willeica]

23 hours ago, pgk said:

Another Grubb lens. This one dates probably from the 1890s but appears to be of 1850s design. It would have been an old design by then and its performance would not have been up to the current lenses which used Jena glass. So why I wonder was such a lens manufactured so much later on. The 40 year production cycle is impressive but somewhat odd.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Very similar in barrel construction to Grubb No 5350, which is in my collection. However, No 5350 has aluminium construction rather than brass. It has a diaphragm aperture which starts at f11.3 which was in the RPS scale which was introduced c 1895. It also has an orange coated lens, indicating, possibly, some scientific purpose. I have shown this one here before, but I am showing this again for comparison with Paul's lens.

3 hours ago, zeitz said:

The cemented doublet of crown and flint glass elements is the first optical formula beyond a simple magnifying glass.  It dates back to telescopes, way beyond the invention of photography.  One of its principle monochrome optical faults is field curvature; since the design is an achromat, there is also significant chromatic aberration.  Field curvature was helped by limiting the max aperture to f6.8 on the subsequent 560mm lens.  The 800mm f6.3 Telyt S achieved a flat field and apochromat performance using a Steinheil cemented triplet with exotic glass elements.

This is correct. Improvements were made from there (the simple crown and flint) involving Grubb's Aplanat from 1857 and then moving on to the multi-lens (called doublets, but which were really air spaced multi doublets) items in the 1860s, with examples from Ross, Dallmeyer and Grubb as well as Steinheil. The real goal was fully compensating elements which has led all the way  to today's modern apochromatic lenses. Peter Karbe went through the history of all of this at our recent LSI conference in Dublin, but his examples tended to be German rather than British or Irish.

There were many rows over who invented what and I have dubbed these the 'Doublet Wars'. 

The fact that the goal was the elimination of aberrations is shown in this note by Thomas Grubb which was probably written about 1856 or 1857. This was on the back of a print of Trinity College Dublin which was shown at the London Photographic Society in 1857 at around the same time that he made his application for a patent for his aplanatic lens design.  On this he mentions that he had taken the image with a 7 1/2 inch lens and the angle of view was either 60 or 70 degrees. He also adds that the railings in front of the College were 'in a curve', thus addressing possible complaints about distortion.

 

Paul and I are doing some research on this matter including the 'Doublet Wars' and I have been lucky enough to have struck up a friendship recently with an eminent professor of optics who is helping us with our research.  I am also going to keep Peter Karbe in the loop about this. Studying the history of optics is one of his hobbies. 

 

William 

[pgk]

5 hours ago, wlaidlaw said:

Thinking of cemented doublets, the Leica Visoflex 560mm f5.6 Telyt lens, sold as late as 1973, was just a simple cemented doublet and it showed. Definition at anything other than the centre of the image was indifferent and only adequate in the centre.

There is a story about Thomas Grubb's son Sir Howard Grubb, the great telescope maker, who, by the late 1880s or early 1890s was struggling to improve the performance of his telescope doublets. The idea of minimising glass to air interfaces in order to reduce flare to an absolute minium was important given that the solution of lens coatings was decades away, which was why doublets were considered highly effective. So he consulted another optical expert in to help - a certain Dennis Taylor. Taylor concluded that improvement was not feasible with doublets and Howard accepted this. However Taylor apparently went off musing about this and the eventual result was his idea for a lens containg the element which was to become known as the Cooke Triplet. I assume that the 1966 560/5.6 was fairly flare resistant?

[willeica]

4 minutes ago, pgk said:

There is a story about Thomas Grubb's son Sir Howard Grubb, the great telescope maker, who, by the late 1880s or early 1890s was struggling to improve the performance of his telescope doublets. The idea of minimising glass to air interfaces in order to reduce flare to an absolute minium was important given that the solution of lens coatings was decades away, which was why doublets were considered highly effective. So he consulted another optical expert in to help - a certain Dennis Taylor. Taylor concluded that improvement was not feasible with doublets and Howard accepted this. However Taylor apparently went off musing about this and the eventual result was his idea for a lens containg the element which was to become known as the Cooke Triplet. I assume that the 1966 560/5.6 was fairly flare resistant?

All of this work was incremental and progressive. Peter Karbe more or less traced the same developments in his talk in Dublin, but his examples tended not to be British. I would like to see him publishing his piece which was a completely new piece of work from him and which has not been shown anywhere else to date. Unlike the other speakers, he did not send his presentation to me, but used his own laptop because of the need for special characters and software. 

On another point, the extent to which people knew what their competitors were doing, long before the internet, telephone and telegraph and even newspapers and magazines with photographs, fascinates me. A lot of the discussion and argument was done through the pages of the Photographic Journal, but often with very few diagrams and drawings. 

William 

[wlaidlaw]

2 hours ago, pgk said:

There is a story about Thomas Grubb's son Sir Howard Grubb, the great telescope maker, who, by the late 1880s or early 1890s was struggling to improve the performance of his telescope doublets. The idea of minimising glass to air interfaces in order to reduce flare to an absolute minium was important given that the solution of lens coatings was decades away, which was why doublets were considered highly effective. So he consulted another optical expert in to help - a certain Dennis Taylor. Taylor concluded that improvement was not feasible with doublets and Howard accepted this. However Taylor apparently went off musing about this and the eventual result was his idea for a lens containg the element which was to become known as the Cooke Triplet. I assume that the 1966 560/5.6 was fairly flare resistant?

Paul, 

The 560/5.6 Telyt had such an enormous lens hood, I had guessed that flare might have been an issue, so never tried it without the hood. The hood is the Vulkanit covered bit at the front of the lens. 

Wilson

 

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[pgk]

19 minutes ago, wlaidlaw said:

The 560/5.6 Telyt had such an enormous lens hood, I had guessed that flare might have been an issue, so never tried it without the hood. The hood is the Vulkanit covered bit at the front of the lens.

I wonder what coating(s) were applied? Single coating I would guess, which would help, but a multi-coated multi element lens would no doubt be a much better performer. It would have been from just before the era when Japanese makers started using fluorite (very late 1960s) and would have been thoroughly outclassed when these became available.

[wlaidlaw]

56 minutes ago, pgk said:

I wonder what coating(s) were applied? Single coating I would guess, which would help, but a multi-coated multi element lens would no doubt be a much better performer. It would have been from just before the era when Japanese makers started using fluorite (very late 1960s) and would have been thoroughly outclassed when these became available.

Thinking about it, the 560, the lens was not even cemented. It fell into the two elements when I took it out (the 400 head was a three element lens). I took the lens out to clean it (badly needed) and it did improve a little. Given mine was made in 1967, I guessed that the coating might have been the old fashioned drip coating, so was very careful with the cleaning. I used warm soapy water, then a rinse in distilled water and a final rinse in methyl alcohol. 

Wilson

Edited December 29, 2022 by wlaidlaw

[pgk]

38 minutes ago, wlaidlaw said:

Thinking about it, the 560, the lens was not even cemented.

I have a Grubb Telescope from 1893 of similar construction. An uncemented doublet. Its surprisingly good although modified witha dolland Barlow eyepiec fitted instead of the original.

[willeica]

4 hours ago, wlaidlaw said:

Paul, 

The 560/5.6 Telyt had such an enormous lens hood, I had guessed that flare might have been an issue, so never tried it without the hood. The hood is the Vulkanit covered bit at the front of the lens. 

Wilson

 

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Laney on your lens, Wilson. It seems that the lens elements should be cemented achromats.

The optical design is simple, but both Paul and I have got great results from using 19th Century Grubb Aplanats which are just crown and flint elements cemented together. Paul can remind me, but did I read somewhere recently that some early lens elements were held together with castor oil ?

William 

 

[wlaidlaw]

William, 

There was no evidence of the elements ever having been cemented on my 560. I bought it from a retired oil field engineer, who had bought it new in the middle east and basically never used it, so I doubt he would have disassembled it and separated the cemented doublet. I wonder if Laney found out it was a doublet and just assumed it was cemented or the alternative is that there was an error at the factory and my group missed out on the cementing process. Although it was not a great performer, it was probably too good to be missing an essential part of the lens like cementing. The lens elements were a very good fit on each other and would hold together with just air pressure, to the extent that it was difficult to separate them once I had cleaned them. 

Wilson

[Advertisement]

Hallo,

Look here: Interesting Leica gear

[pgk]

10 hours ago, willeica said:

Paul can remind me, but did I read somewhere recently that some early lens elements were held together with castor oil ?

Not sure whether it was castor oil William, but I do remember reading something about oil being used. I have also read that some doublets can perform quite satisfactorily even if not cemented (as both Wilson's and my experiece shows). I assume that this depends on the accuracy to which the lens surfaces are made? Handgrinding can achieve an accuracy of as little as 1/4 wavelength of light according to one book I have, which I find quite extraordinary.