Leitz Xenon 5cm f/1.5 Brief Guide - Rumors and Facts

[willeica]

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6 hours ago, derleicaman said:

Greetings to you all. The Xenon has always been a favorite of mine, and currently I have seven in my collection. I don’t know if it is the romantic notion of a high speed lens from the early days of the Leica, or just the name itself. It’s just cool!

Anyway, I am extending an invitation to you all here to write an in depth article on the Xenon, or perhaps a series of articles for the LHSA Viewfinder. I am thinking something along the lines of development, production and variations and the patent story. I did include one of my Xenons in my Bokeh Kings article a few years ago.

Well, who’s up for the challenge? William, Tears Everywhere, pgk, Roydonian? Let’s do it!

Thanks Bill, I'm happy to throw in my few pennies/cents. I'm with Paul (pgk) in saying that this is a story which does not begin with Schneider and end with Leitz. While any magazine article must have boundaries, the story of camera lens development is a continuous one from the 1840s up to the present and, even then, the story begins way before that period. In the Royal Dublin Dublin Society (RDS), where I am a member, we have an original example of the first edition of Newton's Opticks which was published in 1704 and which was the cornerstone of a lot of subsequent optical studies. I recently had a chance to inspect it and found that someone had actually borrowed the book on a library ticket around 1960. Thankfully, the book was returned within the requisite two weeks as the most recent copy of the original edition which sold at auction fetched about $90,000.

I have not contacted Jim Lager yet about this specific Xenon topic as the details were coming in very thick and fast over the weekend. I'm also looking around for a topic for a possible LHSA ZOOM meeting hosted from Dublin during the Summer while we are all in full or semi lockdown. I'm trying to find a 'vintage theme' that will engage members. 

1 hour ago, Tears Everywhere said:

I should create a new topic:
Romance of the three optical giants: Taylor Hobson, Schneider and Leica. 😄

Tears Everywhere, you seem to have a lot of material. I have written over 40 articles on photography and cameras, a lot of them about vintage Leicas, for various publications and websites over the past 5 years and I would also be happy to give a hand with any drafting for a Viewfinder article. 

William

[luigi bertolotti]

1 hour ago, willeica said:

... the story of camera lens development is a continuous one from the 1840s up to the present and, even then, the story begins way before that period. In the Royal Dublin Dublin Society (RDS), where I am a member, we have an original example of the first edition of Newton's Opticks which was published in 1704...

William

and about asphericals... 😉 (trivial wikipedia search...)

"Early attempts at making aspheric lenses to correct spherical aberration were made by René Descartes in the 1620s, and by Christiaan Huygens in the 1670s; the cross-section of the shape devised by Descartes for this purpose is known as a Cartesian oval...."

[willeica]

58 minutes ago, luigi bertolotti said:

"Early attempts at making aspheric lenses to correct spherical aberration were made by René Descartes in the 1620s, and by Christiaan Huygens in the 1670s; the cross-section of the shape devised by Descartes for this purpose is known as a Cartesian oval...."

And Canaletto invented Photoshop! Experiments with light and optics go back a very long way to when somebody found a rock crystal and observed how it transformed light transmitted through it. Descartes, Huygens and Newton were just some of the many geniuses who advanced our knowledge of optics. Wedgewood and others were carrying out what might be deemed to be experiments with photography in the 18th Century. Most 'new knowledge' is built upon already 'known knowledge'.  Barnack and Berek did not create Leicas out of 'thin air' but rather they built upon what came before them. The interesting thing, though, is that despite the number of patents thrown about here, very few cases have actually arisen where someone has sued successfully in respect of patented lens or camera designs, even though the amount of copying has been very large. As Paul (pgk) has pointed out, shared knowledge is very much the key to progress. If patents had held good we might just have got past folder cameras with glass plates at this stage.

William

[pgk]

From Sid Ray's book "The Photographic Lens":

"The double Gauss Rodenstock and Busch formed a symmetrical design using two Gauss telescope objectives front to front with a central stop. This gave an excellent flat field and an aperture of f/6.3 was possible covering 60 degrees even with the old glass types. [Example; Ross Homocentric lens] In 1896 Rudolph replaced the divergent inner menisci with meniscus cemented doublets to give the Planar.

The double Gauss was ..... dormant  until the 1920s as it had to compete with less expensive triplets was was revived by Lee of TTH who used modern glass and asymmetry to give the Opic and Speed Panchro designs covering 50 degrees at f/2. These met the demands of the motion picture industry ..... made it possible to film by ..... tungsten lamps instead of noisy arc lamps outlawed by sound recording.

The introduction of the Leica Camera gave further incentive to large aperture lens design. Development was by the usual manner of 'splitting' and 'compounding' of the front and rear elements of the cemented doublets. ..... high refractive index glass has helped .....Most modern large aperture lenses are double Gauss derivatives (1979)."

And FWIW Speed Panchros for motion picture use are still sought after, and are still expensive, and are still in use. They can be refurbished and remounted in modern barrels for use on current motion picture cameras. This is an expensive thing to do and refurbished and remounted Speed Panchro lenses make many Leica lenses seem like bargains!

So it could be said that the Leica Camera emerged because of motion pictures, and some of its lenses did too. If the Leica came out of silent films, the Xenon was as a result of 'talkies'.

[roydonian]

There was a proposal - around 15 years ago, I think - to build a batch of Speed Panchro lenses in a Leica rangefinder-coupled mount. This was reported in the newsletter of what was then the Leica Historical Society, and contact details were given so that potential purchasers could express their interest.

[Tears Everywhere]

12 minutes ago, pgk said:

The double Gauss was ..... dormant  until the 1920s as it had to compete with less expensive triplets was was revived by Lee of TTH who used modern glass and asymmetry to give the Opic and Speed Panchro designs covering 50 degrees at f/2. These met the demands of the motion picture industry ..... made it possible to film by ..... tungsten lamps instead of noisy arc lamps outlawed by sound recording.

One reason was Zeiss not only patented Planar in Germany, but also in US and British, which limited further development of 6-element Gauss for decades.
The second reason was coating. There were non-Planar type Gauss lenses, such as Beck Isostigmar, but too many air contacted surfaces making it sensitive to flare in practical using.

Lee is the right man, in the right place, at the right time. The patent of Planar had expired. Cooke was the first and the only company held coating technology. 
Then TTH OPIC came to our world.

[pgk]

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27 minutes ago, roydonian said:

There was a proposal - around 15 years ago, I think - to build a batch of Speed Panchro lenses in a Leica rangefinder-coupled mount.

Some are being converted as they are available on eBay. Whether these are 'pukka' conversions or one-offs I don't know. Even tatty Speed Panchros seem to go for high prices (or they are being asked anyway).

8 minutes ago, Tears Everywhere said:

One reason was Zeiss not only patented Planar in Germany, but also in US and British, which limited further development of 6-element Gauss for decades.
The second reason was coating. There were non-Planar type Gauss lenses, such as Beck Isostigmar, but too many air contacted surfaces making it sensitive to flare in practical using.

Indeed. Sid Ray does go into this but I'm not that good a copy typing! It is interesting that it required aspheric elements to improve performance to the standard of lenses offered by Leica today. And they are better but older lenses are no slouches often in performance terms. I'm just using a Mountain Elmar lens on a Sony A7II and resolution and colour differentiation is surprisingly good - but an effective hood is absolutely essential to minimise veiling flare. Its small size (and aperture) help too.

[Pyrogallol]

23 hours ago, luigi bertolotti said:

Could this be a cosequence of the glass type ? After all, many htings happened in the world between the first production runs of Xenon and the first Summarit... Marco Caviina, on his article on Leitz 50mm lenses, does report the detail of glass types but it is not clear if he refers to Xenon or to Summarit : btw, Summarit was also manufactured in Midland factory, iirc...

And,... what about the "Roentgen Xenon" ? 😉 Was it simply a different mount of exactly the same lens assembly, or a slightly different design ?

 

Read here a reference to the x ray use, then saw this

https://www.ebay.co.uk/itm/Leica-X-Ray-Black-w-1-5-5cm-Xenon-Leitz-New-York/264717776607?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D225114%26meid%3Ddb90f825b0f64eb29be8a31b345d0d22%26pid%3D100667%26rk%3D7%26rkt%3D8%26mehot%3Dnone%26sd%3D193450721708%26itm%3D264717776607%26pmt%3D0%26noa%3D1%26pg%3D2334524%26brand%3DLeica&_trksid=p2334524.c100667.m2042

[wizard]

Am 1.5.2020 um 18:46 schrieb willeica:

Generally patents in those days applied only in the country where the patent was issued.

That is still true today, as a patent is issued by a country's patent office (which may only grant patents with respect to that country's territory). While regional patent offices do exist today (for example the European Patent Office), which have been given the right to grant a patent potentially having effect in many more than just one country, even patents (e.g. a European patent) granted by those supranational authorities are no unitary patents, but once granted consist of a bundle of national patents (e.g. a German patent, a British patent, a French patent and so on in the case of a European patent). Obtaining sound patent protection requires applying for a patent in many countries, and is, therefore, quite expensive.

[Hello]

Also, interestingly, you have my serial number in your list. Fascinating.

[derleicaman]

On 4/30/2020 at 1:31 PM, Tears Everywhere said:

After review historical documents and a record of 200 samples, I am trying to solve those rumors about Leitz Xenon.❤️

 

Brief Conclusion:

1. The total of Taylor-Hobson (TTH) engraved Xenon would be close to 2000 lenses.

2. Xenon was designed and made under the Leica patent issued in 1937, with the collaboration of Schneider.

3. However, that patent was a modification based on the US and British patent of TTH.
It needs TTH's license if selling Xenon in those countries. (So did the early Summarit.)

4. All TTH-Xenon were in feet scale, in order to sell in US and British.

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 pulled out the one Xenon I have which does not have fog or other issues, and was the one that I used in the LHSA article Bokeh Kings. It is serial # 288113, DRPa, Marked US Patent, scale in feet and has three rings. According to your table, it was the 13th lens made, which is very cool! It is uncoated and looks like it was never tampered with over the years. I've probably had it for 25-30 years.

Took a few test shots with it and it does very well. Appears to be sharp in the center wide open, and not suffering from the "dreamy" look which is so typical of many of these lenses along with the Summarits. There is some vignetting. Stopping down to F/3.2, things improve sharpness wise in the field and the vignetting has all but disappeared.

I have a number of Summarits as well, but there is just something so appealing about the Xenon. I'll have to dig out the other Xenons and I will report on the details of those.

[Tears Everywhere]

8 hours ago, derleicaman said:

Took a few test shots with it and it does very well. Appears to be sharp in the center wide open, and not suffering from the "dreamy" look which is so typical of many of these lenses along with the Summarits. There is some vignetting. Stopping down to F/3.2, things improve sharpness wise in the field and the vignetting has all but disappeared.

Wow 😃
Actually, Leitz Xenon is a quite sharp lens in lab, although not as sharp as modern aspherical successor. But those uncoated glasses making it easily scratched or oxidized.  

Edited May 5, 2020 by Tears Everywhere

[Tears Everywhere]

On 5/3/2020 at 9:43 PM, willeica said:

Hartmut Thiele shows ranges for up to 6,505 Xenon serial numbers as having been assigned, but the Blue Book only shows 6190 as having been manufactured between 1936 and 1950. Thiele's list needs to be read carefully as Leitz often did not use the full number ranges assigned.  

According to my record, from 0 to 9, each digit appears in the hundred place of serial number. There might be no gap in serial number.
The only exception is the end of each batch, I haven't saw a lens with serial number 4269xx.
I also never saw a Xenon with 4919xx, but that should be assigned to Summarit prototype. 

The total production of all version Xenon would be close to 6300.

Edited May 5, 2020 by Tears Everywhere

[willeica]

1 hour ago, Tears Everywhere said:

According to my record, from 0 to 9, each digit appears in the hundred place of serial number. There might be no gap in serial number.
The only exception is the end of each batch, I haven't saw a lens with serial number 4269xx.
I also never saw a Xenon with 4919xx, but that should be assigned to Summarit prototype. 

The total production of all version Xenon would be close to 6300.

Thiele’s list is only an approximate guide, no matter what lens we are talking about. Leitz/ Leica generally did not use all serial numbers nor were they always used in strict numeric order. That is why I used the word ‘assigned’. Your figure of 6300 manufactured is not too far away from the 6190 shown as being manufactured in the Blue Book. Then there are the Xenon lenses which seem to have been made by Schneider, as mentioned by Lex ( Sandro). 
 

Your figure of 2,000 lenses with TTH matches the number used by Dumur when speaking to Weaver and, so, perhaps he was talking about TTH examples only?
 

That is numbers/numbering more or less accounted for. As for copyright, whether breaches actually occurred 90 to 100 years ago may just be a moot point now as no cases testing that hypothesis actually occurred at that time and many lenses with similar features were being constructed and/or manufactured during that period. Lens design by that time in many ways represented a ‘language’ rather pure ‘invention’ and, so, while patents were awarded for different designs, actually arguing successfully that breaches in respect of specific ‘intellectual property’ had occurred might have been difficult. Leitz definitely erred on the side of caution in respect of Schneider and , where applicable, TTH. What we don’t seem to know is whether any commercial consideration existed alongside this caution. Or do you know something about this as well?

William

 

 

[luigi bertolotti]

On 4/30/2020 at 8:31 PM, Tears Everywhere said:

After review historical documents and a record of 200 samples, I am trying to solve those rumors about Leitz Xenon.❤️

 

Brief Conclusion:

1. The total of Taylor-Hobson (TTH) engraved Xenon would be close to 2000 lenses.

2. Xenon was designed and made under the Leica patent issued in 1937, with the collaboration of Schneider.

3. However, that patent was a modification based on the US and British patent of TTH.
It needs TTH's license if selling Xenon in those countries. (So did the early Summarit.)

4. All TTH-Xenon were in feet scale, in order to sell in US and British.

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!

Tears... if you like, add my one to your list : 491.488 , meter scale, 4 rings, DRP, no patents

Edited May 5, 2020 by luigi bertolotti

[pgk]

Out of interest there is a Schneider Xenon on eBay currently at a silly price https://www.ebay.co.uk/itm/Schneider-Xenon-F1-5-50mm-Leica-LTM-Original-mount-w-RF-coupling/223951086829?hash=item34248664ed:g:OW0AAOSwHcxerx0C and this is in LTM mount, however it is not clear whether it is RF coupled. It may be and if it is it does seem odd that Schneider would produce a lens to compete with Leica's.

[luigi bertolotti]

1 hour ago, pgk said:

Out of interest there is a Schneider Xenon on eBay currently at a silly price https://www.ebay.co.uk/itm/Schneider-Xenon-F1-5-50mm-Leica-LTM-Original-mount-w-RF-coupling/223951086829?hash=item34248664ed:g:OW0AAOSwHcxerx0C and this is in LTM mount, however it is not clear whether it is RF coupled. It may be and if it is it does seem odd that Schneider would produce a lens to compete with Leica's.

Very odd lens indeed... 🙄 even if , for that price, some "transplant" can worth the job... 😁... scale to 16 and international f stops... but who knows, if the original was a "wartime" item ? Schneider records date # 1.800.000 at June 42 (and # 2.000.000 at September 48) ... surely times of not standard competition between German manufacturers... anyone had to fulfill orders probably for military and government related customers only, or next to...

Edited May 5, 2020 by luigi bertolotti

[Tears Everywhere]

1 hour ago, pgk said:

Out of interest there is a Schneider Xenon on eBay currently at a silly price https://www.ebay.co.uk/itm/Schneider-Xenon-F1-5-50mm-Leica-LTM-Original-mount-w-RF-coupling/223951086829?hash=item34248664ed:g:OW0AAOSwHcxerx0C and this is in LTM mount, however it is not clear whether it is RF coupled. It may be and if it is it does seem odd that Schneider would produce a lens to compete with Leica's.

It should be one of those 180 Xenon made post war, as mentioned by Sandro.

[willeica]

https://www.photo.net/discuss/threads/ltm-xenon-1-5-some-shots.236819/

William

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Hallo,

Look here: Interesting Leica gear

[luigi bertolotti]

4 minutes ago, willeica said:

https://www.photo.net/discuss/threads/ltm-xenon-1-5-some-shots.236819/

William

Right... I found also a pair on past Westlicht auctions (2008 - sold at rather reasonable prices, btw) ; so not a transplant... but the asked price is really silly...

Edited May 5, 2020 by luigi bertolotti