Counsel Posted February 5, 2023 Share #201 Posted February 5, 2023 (edited) Advertisement (gone after registration) Apparently there is a misunderstanding about what conclusions can be drawn from the patent literature with regard the designer of a product. A product may be subject to the teaching of several patents. This is also the case with the Leitz Xenon. This was not developed by Taylor Hobbs, but the teachings of the Taylor-Hobbs patent were used in the design of the lens by Albrecht William Tronnier, a chief designer at Schneider, Kreuznach (Xenar, Xenon) and later (Schneider’s subsidiary) Isco Göttingen, as well as at Voigtländer (Skopar, Ultron, Septon) after the war. Tronnier also developed the Leitz Xenon as an employee of Schneider - Kreuznach Quote: „double Gauss type with 7 and more lenses, extended XENON type This type was created by attaching a rear lens to the 6-lens XENON for better correction and gaining one f-stop of light intensity. The first 35mm lens of this construction was the Leitz Xenon 1936 - built under license by Schneider (designed by its employee Tronnier) and a competitor of the Zeiss Sonnar - which it did not reach in terms of performance. Only with the availability of new types of glass could the construction be satisfactory and was chosen for a while for f/1.4 standard lenses in the 1960's (also for 1.2/58 Canon 1962)“ https://www.klassik-cameras.de/Biotar.html If you want to report on the development of early optical lenses, it is essential to master the German language. Because in Germany the most important optical developments were made in the period before the Second World War and long afterwards. Edited February 5, 2023 by Counsel Quote Link to post Share on other sites More sharing options...
Advertisement Posted February 5, 2023 Posted February 5, 2023 Hi Counsel, Take a look here Leitz Xenon 5cm f/1.5 Brief Guide - Rumors and Facts. I'm sure you'll find what you were looking for!
willeica Posted February 5, 2023 Share #202 Posted February 5, 2023 20 minutes ago, Counsel said: built under license by Schneider 'by' or 'from'? 21 minutes ago, Counsel said: If you want to report on the development of early optical lenses, it is essential to master the German language. Because in Germany the most important optical developments were made in the period before the Second World War and long afterwards. I agree 100% . This is not just the case for Leica/Leitz, but for all types of German made cameras, lenses and shutters made in the 1920s, 30s and even into the post war period. There are many aspects of the German photographic industry that have not been written about at all in English, whereas there are many such books in German. This link gives some idea of what I am talking about: https://www.lindemanns.de/shop/photobookshop/camera-history-new-arrived.php Most of these books are only available in German. William Quote Link to post Share on other sites More sharing options...
Counsel Posted February 5, 2023 Share #203 Posted February 5, 2023 The Leitz Xexon first was actually even built by Schneider. Later an improved version (better glass? Coating?) was designed by Leitz (Dr. Max Berek ?) and sold as Leitz Summitar 1,5 50 mm Quote Link to post Share on other sites More sharing options...
Tears Everywhere Posted February 6, 2023 Author Share #204 Posted February 6, 2023 2 hours ago, Counsel said: Quote: „double Gauss type with 7 and more lenses, extended XENON type This type was created by attaching a rear lens to the 6-lens XENON for better correction and gaining one f-stop of light intensity. The first 35mm lens of this construction was the Leitz Xenon 1936 - built under license by Schneider (designed by its employee Tronnier) and a competitor of the Zeiss Sonnar - which it did not reach in terms of performance. Only with the availability of new types of glass could the construction be satisfactory and was chosen for a while for f/1.4 standard lenses in the 1960's (also for 1.2/58 Canon 1962)“ https://www.klassik-cameras.de/Biotar.html If you want to report on the development of early optical lenses, it is essential to master the German language. Because in Germany the most important optical developments were made in the period before the Second World War and long afterwards. The web site you mentioned is a highly misleading of optical history. The world's first Double-Gauss type with attaching a rear lens, 7 or more elements in 5 groups, was the Taylor Hobson Ultra Speed Panchro made in 1928. But it was designed for cinematograph, and Leica 35mm camera system was not yet sale in market. That's why first 35mm lens of this type is Leitz Xenon 1936, but not the first lens in optical history. If you know German language, you should take a look at German patent DE565566 applied in 1930, that was a 6 element Xenon lens with additional rear lens group (8 elements in total). In that patent, Schneider said "Derartige Erweiterungen optischer Systeme sind an sich bekannt und für Taylor-Objektiv" which means Taylor company already had product of this type prior than Schneider. So Schneider had to change the rear lens group into doublet, to avoid the Taylor Hobson design. Quote Link to post Share on other sites More sharing options...
Counsel Posted February 6, 2023 Share #205 Posted February 6, 2023 Sorry, I don't know where you see the problem. This website (and me) does not claim that this lens design of the Leitz Xenon was the very first of its kind. However, it was - and this is historically undisputed - the first lens construction for the new (Leitz/Barnack) 35 mm format for photography. Quote Link to post Share on other sites More sharing options...
Tears Everywhere Posted February 6, 2023 Author Share #206 Posted February 6, 2023 14 minutes ago, Counsel said: Sorry, I don't know where you see the problem. This website (and me) does not claim that this lens design of the Leitz Xenon was the very first of its kind. However, it was - and this is historically undisputed - the first lens construction for the new (Leitz/Barnack) 35 mm format for photography. That website called the Gauss type of 7 or more elements as "extended Xenon type" but do not have even one word mention about Taylor Hobson Speed Panchro family. It also said the extended type was created by "attaching a rear lens to Xenon". It might misleading that Tronnier of Schneider invented all of them. I also have a very rare Schneider Xenon f/1.5 lens made in 1929 for cinematography, it did not has the optical construction as the author said. 😊 Quote Link to post Share on other sites More sharing options...
Counsel Posted February 6, 2023 Share #207 Posted February 6, 2023 Advertisement (gone after registration) Sorry, I still don't understand what the problem is. Why would the website author mention a lens that was not designed for 35mm cameras? Incidentally, Schneider/Leitz expressly acknowledged that the Leitz Xenon also used the teaching of the Hobson Webb patent, which, as far as I remember, was invented by Lee. Apparently even a license was taken. By the way, I can only congratulate you on having such a beautiful old lens for Cinematography. It had been designed by Albrecht William Tronnier at Schneider Kreuznach, too. Nobody did say, that the construction was identical with the Leitz Xenon 1,5/50. It was the reason, however, why Leitz not having a lens to compete Zeiss with its famous Sonnar 1,5/50 of the Contax requested Schneider to develop an adequate lens. This task was performed by Tronnier, too. Quote Link to post Share on other sites More sharing options...
Tears Everywhere Posted February 6, 2023 Author Share #208 Posted February 6, 2023 1 hour ago, Counsel said: Sorry, I still don't understand what the problem is. Why would the website author mention a lens that was not designed for 35mm cameras? Incidentally, Schneider/Leitz expressly acknowledged that the Leitz Xenon also used the teaching of the Hobson Webb patent, which, as far as I remember, was invented by Lee. Apparently even a license was taken. https://www.klassik-cameras.de/Biotar.html In part I of the website you mentioned, it tracked back to 1916 the Minor Ultrastigmat lens and 1922 Ernostar lens. All of them are not for 35mm camera. In part II, it tracked back to 1893 the Goerz lens. Another German optical design not for 35mm camera. In part III for 7-element Gauss lens, it tracked to 1929 Xenon f/1.5 and said Leitz Xenon 1936 is the first of this type for 35mm camera, without a word on Xenon TTH patent. Is 1929 Xenon f/1.5 the first Gauss lens with additional group?? I have one, it was totally different to what the website mentioned. It looks like the author putting too much on German product but the real optical history is quite different. 😊 Quote Link to post Share on other sites More sharing options...
Counsel Posted February 6, 2023 Share #209 Posted February 6, 2023 I do not believe that the author deliberately placed too little value on scientific work in other countries. As you can see, he mostly discussed the German camera industry, and that happened to be the most advanced before and for a long time after World War II. That all changed when the Japanese took over. Today the German camera industry is only a shadow of itself. Quote Link to post Share on other sites More sharing options...
Tears Everywhere Posted January 21, 2024 Author Share #210 Posted January 21, 2024 Hello to everyone. Four years ago I started this thread about those rumors of Leitz Xenon. My recent research has interesting findings about Leica Noctiluxes. Before making a conclusion, is there any member have personal connection to Waltzer, can help me to confirm some questions? For example, the official diagram of Noctilux 50/0.95 clearly shows the last surface is aspheric. However, another arrow of aspheric lies between 2nd and 3rd surface. Most users said that means 3rd surface is aspheric. I am looking for a formal answer. @derleicaman Quote Link to post Share on other sites More sharing options...
UliWer Posted January 21, 2024 Share #211 Posted January 21, 2024 (edited) vor 3 Stunden schrieb Tears Everywhere: Before making a conclusion, is there any member have personal connection to Waltzer, can help me to confirm some questions? I don't think you need a "personal connection". You may just write to "info(at)leica.com" and I am sure you will get an answer. P.S.: The technical sheet for the Noctilux is quite explicit about the aspherical elements: https://leica-camera.com/de-DE/fotografie/objektive/m/noctilux-m-1-095-50mm-asph-schwarz/technische-daten Edited January 21, 2024 by UliWer Quote Link to post Share on other sites More sharing options...
Tears Everywhere Posted January 22, 2024 Author Share #212 Posted January 22, 2024 10 hours ago, UliWer said: I don't think you need a "personal connection". You may just write to "info(at)leica.com" and I am sure you will get an answer. You mean the info(at)leica-camera.com. The URL "leica.com" belongs to Leica Microsystems. In my research, I found something different to those public data.🤔 Quote Link to post Share on other sites More sharing options...
UliWer Posted January 22, 2024 Share #213 Posted January 22, 2024 vor 5 Minuten schrieb Tears Everywhere: You mean the info(at)leica-camera.com. The URL "leica.com" belongs to Leica Microsystems. Yes, of course! Quote Link to post Share on other sites More sharing options...
luigi bertolotti Posted January 22, 2024 Share #214 Posted January 22, 2024 23 hours ago, Tears Everywhere said: Hello to everyone. .... For example, the official diagram of Noctilux 50/0.95 clearly shows the last surface is aspheric. However, another arrow of aspheric lies between 2nd and 3rd surface. Most users said that means 3rd surface is aspheric. I am looking for a formal answer. @derleicaman 3rd surface IS aspherical, according to the data sheet , so I think that Leica would by sure confirm what they write in public docs... If you have found some discrepancies, based on technical inspections, it is an intriguing matter... 😉 can you give some further detail ? I don't think that Leica would prosecute you if you put in discussion some of their public docs in a private community like our Forum... 😗 1 Quote Link to post Share on other sites More sharing options...
Tears Everywhere Posted January 22, 2024 Author Share #215 Posted January 22, 2024 1 hour ago, luigi bertolotti said: 3rd surface IS aspherical, according to the data sheet , so I think that Leica would by sure confirm what they write in public docs... If you have found some discrepancies, based on technical inspections, it is an intriguing matter... I don't think those Leica public data sheets is 100% correct. For example, the diagram of 11686 Noctilux 50/1.2 ASPH has two versions, the rear aspheric surface is different. Both came from Leica official data sheets. 🤔 @derleicaman 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! Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/309062-leitz-xenon-5cm-f15-brief-guide-rumors-and-facts/?do=findComment&comment=5002202'>More sharing options...
UliWer Posted January 22, 2024 Share #216 Posted January 22, 2024 For the original 1:1.2 Noctilux I'd rely on Marco Cavina: http://www.marcocavina.com/articoli_fotografici/Leica_Noctilux_M__50_1,2/00_pag.htm 1 Quote Link to post Share on other sites More sharing options...
Tears Everywhere Posted January 22, 2024 Author Share #217 Posted January 22, 2024 1 hour ago, UliWer said: For the original 1:1.2 Noctilux I'd rely on Marco Cavina: Marco Cavina is a highly respected expert on optics. But for original Noctilux 1966, he provides not more than Leica public data. Anyway thanks.😉 Quote Link to post Share on other sites More sharing options...
willeica Posted January 22, 2024 Share #218 Posted January 22, 2024 2 hours ago, Tears Everywhere said: I don't think those Leica public data sheets is 100% correct. For example, the diagram of 11686 Noctilux 50/1.2 ASPH has two versions, the rear aspheric surface is different. Both came from Leica official data sheets. 🤔 @derleicaman 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! I can ask Peter Karbe about this, but, as before, you need to be more specific about the point you are making. Peter is a 'facts man' and there is no point in going to him and saying that 'I know something ' or 'a person I know says something'. Can you 1. be more specific about what you are saying, and, also , 2. can say how or why this matters? William 1 Quote Link to post Share on other sites More sharing options...
Michael Geschlecht Posted January 23, 2024 Share #219 Posted January 23, 2024 (edited) Hello Tears Everywhere, Welcome to the Forum, Or, it could be a printing error. One way or the other. There have been occasional printing or data errors in various Leitz/Leica data sheets, etc. over the years. The 2 lens diagrams look reasonably similar. Best Regards, Michael Edited January 23, 2024 by Michael Geschlecht 1 Quote Link to post Share on other sites More sharing options...
Tears Everywhere Posted January 23, 2024 Author Share #220 Posted January 23, 2024 17 hours ago, willeica said: I can ask Peter Karbe about this, but, as before, you need to be more specific about the point you are making. Please give me some days to collect and refine questions.😍 1 Quote Link to post Share on other sites More sharing options...
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