Jump to content

Recommended Posts

Advertisement (gone after registration)

15 hours ago, Roland Zwiers said:

I am curious after the meaning of 4201; does this stand for the 'Kleinfilmkamera' under consideration

Hello Roland,

I can confirm 

4201 is the factory “Designation” for “Kleinfilmkamera (Model 1)”

”Kamera” is the description for a pre 0 series camera 

Photo courtesy of Dirk Mann

Regards

Alan

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!

Edited by beoon
  • Like 1
Link to post
Share on other sites

Am 1.8.2023 um 11:59 schrieb willeica:

Here is a blueprint for the 5 element Anastigmat. It is dated 22.9.23

Dirk Mann shown once a drawing of 4 elements Anastigmat (attached below). Mechanical construction is very much like later for Elmax/Elmar. The note at the bottom of drawing shown by William says to use the mount of Summar 64.

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!

  • Thanks 1
Link to post
Share on other sites

On 8/1/2023 at 7:39 AM, Roland Zwiers said:

So as a precaution Max Berek may have used different types of optical glass for the front and rear lens elements.But these elements may have discoloured over time on exposure to oxygen.

Just curious (and apologies if you've said this already) but what is the source of the claim that the glass became discoloured or deteriorated?

Link to post
Share on other sites

7 hours ago, Roland Zwiers said:

Still, The 1923 Leica Pocket Guide 9th Edition may be based on information that I have overlooked.
After all, my passion is to dig in pre-war sources.
If a new piece of information comes along, I am very willing to adapt my working hypothesis again.

 

The 9th Edition is just the same as the 8th Edition. I've always been confused about 4/5 element issue with the Anastigmat, but the source of the information may well indeed be down to viewing patents and/or drawings/blueprints and reaching conclusions based on that. The handover between the Elmax and Elmar probably needs more work, particularly as regards the timing of the introduction of the 4 element design, but I would never doubt what Ottmar says.

5 hours ago, beoon said:

Hello Roland,

I can confirm 

4201 is the factory “Designation” for “Kleinfilmkamera (Model 1)”

”Kamera” is the description for a pre 0 series camera 

Photo courtesy of Dirk Mann

Regards

Alan

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 agree, Alan. 4201 seems to be the code for the 35mm 'kleinfilmkamera' project.

1 hour ago, jerzy said:

Dirk Mann shown once a drawing of 4 elements Anastigmat (attached below). Mechanical construction is very much like later for Elmax/Elmar. The note at the bottom of drawing shown by William says to use the mount of Summar 64.

Thanks Jerzy. Do you have a date for this drawing ? I am assuming it predates the blueprint which I posted as it is clearly a 4 element design. 

The Elmar book by Ghisetti and Cavino traces the evolution as follows.

Note to Roland : This shows the evolution path. I don't believe it is intended to be a precise scientific or historical treatise.

William 

 

 

Link to post
Share on other sites

vor 35 Minuten schrieb Anbaric:

but what is the source of the claim that the glass became discoloured

And to add to that question, why would discoloured optical glass be inferior? I thought that optical glass has and should have no noticeable colour anyway. However, if optical glass becomes coloured, as for example with the radioactive lens elements used on the first Summicrons, that got yellowish, this does indeed change the color rendition of a lens and is, therefore, undesirable.

Edited by wizard
correction
Link to post
Share on other sites

Advertisement (gone after registration)

1 minute ago, wizard said:

And to add to that question, why would discoloured optical glass be inferior? I thought that optical glass has and should have no noticeable colour anyway. However, if optical glass becomes coloured, as for example with the radioactive lens elements used on the first Summicrons, that got yellowish, this does indeed change the color rendition of a lens and is, therefore, unddesirable.

I have 19th Century lenses which have 'yellowed' due to the balsam glue they contain, but they take perfect colour images when mounted on a bellows in front of a modern digital camera. With black and white film the effect would be even less, but nothing less than perfection would ever do for Barnack and he kept retesting his creations until the day he died. However, Roland and I have been having discussions on the use of yellow filters on early Leica prototypes for some years now.  This is related to the lack of colour sensitivity in early black and white 35mm films. 

William 

Link to post
Share on other sites

vor 42 Minuten schrieb willeica:

I have 19th Century lenses which have 'yellowed' due to the balsam glue they contain, but they take perfect colour images when mounted on a bellows in front of a modern digital camera. With black and white film the effect would be even less, but nothing less than perfection would ever do for Barnack and he kept retesting his creations until the day he died. However, Roland and I have been having discussions on the use of yellow filters on early Leica prototypes for some years now.  This is related to the lack of colour sensitivity in early black and white 35mm films. 

William, I do appreciate your response, but it does not seem to answer my initial question re the allegedly undesired discoloration of optical glass mentioned by Roland. In my view, a discolored optical glass, that is, an optical glass having no appreciable color, is to be preferred, whereas coloration of optical glass is to be avoided for obvious reasons. Or is there any misunderstanding on my part?

Link to post
Share on other sites

2 hours ago, Anbaric said:

Just curious (and apologies if you've said this already) but what is the source of the claim that the glass became discoloured or deteriorated?

Thank you for this critical question.
In Leica literature there is no explanation for the succession of the 1920 4-element Leitz Anastigmat to the 1922/1923 5-element Leitz Anastigmat,
which would be baptised Elmax in December 1924.
So there is no conclusive source for the deterioration of glass on the 4-element Leitz Anastigmat either.
Ulf Richter (2009) mentions it as a possibility.

We do have a construction drawing for the 5-element Leitz Anastigmat.
And from the German handwriting it is clear that the front and/ or rear elements have been changed twice in 1921-1922.
So I infer this may have been due to deteriorating glass because of exposure to oxygin.
And if this was the case with the 5-element Anastigmat, then that may also be a clue for what had gone wrong with the 1920 Anastigmat.

This is a working hypothesis.
If a more plausible explanation comes available, I am very willing to reformulate the hypothesis.

 

Roland  

    

  • Like 1
Link to post
Share on other sites

1 hour ago, willeica said:

The 9th Edition is just the same as the 8th Edition. I've always been confused about 4/5 element issue with the Anastigmat, but the source of the information may well indeed be down to viewing patents and/or drawings/blueprints and reaching conclusions based on that. The handover between the Elmax and Elmar probably needs more work, particularly as regards the timing of the introduction of the 4 element design, but I would never doubt what Ottmar says.

I agree, Alan. 4201 seems to be the code for the 35mm 'kleinfilmkamera' project.

Thanks Jerzy. Do you have a date for this drawing ? I am assuming it predates the blueprint which I posted as it is clearly a 4 element design. 

The Elmar book by Ghisetti and Cavino traces the evolution as follows.

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!

Note to Roland : This shows the evolution path. I don't believe it is intended to be a precise scientific or historical treatise.

William 

 

 

William,

This is good enough for me 🙂

It shows the design steps between the 4-element Anastigmat of 1920, to the 5-element Anastigmat of 1922-1925, to again a 4-element design after spring 1925.
Note that the names Elmax and Elmar are a bit confusing.
The new 4-element design was originally called Elmax as well (design change, no name change).
After October 1925 the new 4-element design would be called Elmar, so as to avoid a conflict with an Ernemann tradename.

Roland

 

  • Thanks 1
Link to post
Share on other sites

1 hour ago, wizard said:

William, I do appreciate your response, but it does not seem to answer my initial question re the allegedly undesired discoloration of optical glass mentioned by Roland. In my view, a discolored optical glass, that is, an optical glass having no appreciable color, is to be preferred, whereas coloration of optical glass is to be avoided for obvious reasons. Or is there any misunderstanding on my part?

William draws an interesting analogy to other kinds of discolouring.
Canada balsam would indeed cause discolouring over time.
Lens makers could even insert a yellow glass on purpose for colour-correct black-and-white photography.
And so on.
This is not what I had in mind in realation to the 1920 Leitz Anastigmat.

We do not know for certain what made this lens unsuitable for the 1920 Handmuster, for which it was obviously intended.
So I infer (working hypothesis) that Max Berek uses optical glass that deteriorated/ discoloured over time.
To the extent that this reduced its optical qualities, this must have made the lens unsuitable.
And so Max Berek had to start immediately on a new design.

Which must have caused a long delay for the Null-Serie.

Roland  

Link to post
Share on other sites

1 hour ago, wizard said:

William, I do appreciate your response, but it does not seem to answer my initial question re the allegedly undesired discoloration of optical glass mentioned by Roland. In my view, a discolored optical glass, that is, an optical glass having no appreciable color, is to be preferred, whereas coloration of optical glass is to be avoided for obvious reasons. Or is there any misunderstanding on my part?

In (UK) English "discoloured" implies coloured (confusing though it is!) - or perhaps "acquiring a colour after being previously uncoloured".

Link to post
Share on other sites

1 minute ago, Roland Zwiers said:

So there is no conclusive source for the deterioration of glass on the 4-element Leitz Anastigmat either.
Ulf Richter (2009) mentions it as a possibility.

Maybe Ulf Richter has a contemporary source, or there is some clear precedent for this? Is there evidence that some particularly exotic glass was used? Otherwise we should perhaps be sceptical - all lens elements are exposed to the air, except adjacent cemented surfaces. It's easy to imagine lots of scenarios where one design might be preferred over another for final production, depending on cost, ease of manufacture, real-world performance, and potential conflict with the Zeiss patents you mention above. We know that the classic 4-element design was more than satisfactory, and comparative testing may be problematic with optics of this age, but do we know if the fifth element actually improved performance?

Link to post
Share on other sites

In photographic literature on lenses/ optical glass it is well known that some types of optical glass deteriorate over time.
That makes these types less suitable or even unsuitable for photographic purposes.
But glass makers like Goerz and Schott were continuously looking for new types of optical glass with all kinds of innovative specifications.
These specifications were listed in tables so that lens makers could chose the right type of glass for the right lens element.

It is very likely that with new types of optical glass it was not known immediately how resistent they would be against atmoshperic influences.
Or against fingerprints.
Or other misadventures.

So my working hypothesis is that Max Berek chose new optical glass for the front and/or rear elements of the 1920 4-element Anastigmat.
And that after a while he found out that something went wrong.

Based on photographic literature I infer that deterioration because of atmoshperic influences was to blame. 

Max Berek could have chosen to play safe by adopting the optical glass that was used in the Tessar patent.
That was a proven design.
But obviously, Ernst Leitz II did not want to pay royalties.

An interesting question is: was this a strategic mistake?
Suppose Max Berek was allowed to design a Tessar copy in 1919 or 1920 and Ernst Leitz II would have paid a  licence fee for this.
Then it follows that the Null-Serie could already have been tested in the course of 1920!
After 5 years or so the Tessar patent would have expired anyhow!
 

Roland

  

 

 

 

Link to post
Share on other sites

8 hours ago, beoon said:

Hello Roland,

I can confirm 

4201 is the factory “Designation” for “Kleinfilmkamera (Model 1)”

”Kamera” is the description for a pre 0 series camera 

Photo courtesy of Dirk Mann

Regards

Alan

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!

Alan,

Thank you for this design drawing, and thank Dirk Mann as well.
Now the drawing has the date: 8 december 1922.
In my analysis that would combine very well with a design drawing for the coming Null-Serie of 1923.

The first Null Serie cameras were delivered in March 1923.
So one has to include some time for the hand-made production of the cameras and the 5-element Anastigmats.

Leica literature suggests that Oskar Barnack make prototypes first without any design drawing at hand.
That would have to change as soon as he wanted to order a batch of, say, 25 test cameras.
So I would infer that the drawing was made in preparation for the Null-Serie.

One can also infer that Mr. Schäfer made use of the latest prototype for making this drawing.
But that Oskar Barnack was looking over his shoulder so as to suggest futher improvements.

Roland

 

 

 


 

  • Like 1
Link to post
Share on other sites

5 hours ago, jerzy said:

Dirk Mann shown once a drawing of 4 elements Anastigmat (attached below). Mechanical construction is very much like later for Elmax/Elmar. The note at the bottom of drawing shown by William says to use the mount of Summar 64.

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!

Dirk Mann shown once a drawing of 4 elements Anastigmat (attached below). Mechanical construction is very much like later for Elmax/Elmar. The note at the bottom of drawing shown by William says to use the mount of Summar 64.

Jerzy,

I get confused now between all these similar blueprints 🙂

As far as I remember it was William who showed the first blueprint.
It was signed by Mr. Schäfer, it was from the second part of 1923, and it had a reference to the use of the mount of the Summar 64.
I forgot to reply to that Summar 64 aspect.

To me the 4.5/64 Summar is something that belongs to the Ur-Leica and the Pre-Null-Serie prototypes. 
So I am very surprised to see this reference in relation to the 1923 5-element Anastigmat!

William earlier showed a drawing made for Oskar Barnack that calculated the consequence for the lens mount at 1m (316 degrees) when the focal lenght changed from 50mm to 52mm.
As far as I remember a difference in focal lenght of 2mm (from 50 to 52mm) amounted to a longer lens extention of about 0,2mm.  

Now imagine the difference between a 50mm lens and a 64mm lens!
How can you possibly fit a 50mm lens in the lens mount of a 64mm lens while keeping the focussing mechanism adequate between 1m and infinity?
I am at a loss for an explanation.

Roland


 

Link to post
Share on other sites

Jerzy,

The later blueprint by Dirk Mann deserves a reply as well.
But I would like to know what date.
I cannot see at a glance if a 4-element design is the original 1920 Leitz Anastigmat or the later 4-element Elmax/ Elmar of 1925.

Roland  

Link to post
Share on other sites

3 hours ago, wizard said:

William, I do appreciate your response, but it does not seem to answer my initial question re the allegedly undesired discoloration of optical glass mentioned by Roland. In my view, a discolored optical glass, that is, an optical glass having no appreciable color, is to be preferred, whereas coloration of optical glass is to be avoided for obvious reasons. Or is there any misunderstanding on my part?

I would agree that is how the matter would have been perceived. I was just pointing out that lenses with coloration can produce good results. A yellow filter is an example of colorised glass and Roland is convinced that Barnack used yellow filters for early Leica images. The light in those cases would have been received through colorised glass. 

 

1 hour ago, Roland Zwiers said:

Dirk Mann shown once a drawing of 4 elements Anastigmat (attached below). Mechanical construction is very much like later for Elmax/Elmar. The note at the bottom of drawing shown by William says to use the mount of Summar 64.

Jerzy,

I get confused now between all these similar blueprints 🙂

As far as I remember it was William who showed the first blueprint.
It was signed by Mr. Schäfer, it was from the second part of 1923, and it had a reference to the use of the mount of the Summar 64.
I forgot to reply to that Summar 64 aspect.

To me the 4.5/64 Summar is something that belongs to the Ur-Leica and the Pre-Null-Serie prototypes. 
So I am very surprised to see this reference in relation to the 1923 5-element Anastigmat!

William earlier showed a drawing made for Oskar Barnack that calculated the consequence for the lens mount at 1m (316 degrees) when the focal lenght changed from 50mm to 52mm.
As far as I remember a difference in focal lenght of 2mm (from 50 to 52mm) amounted to a longer lens extention of about 0,2mm.  

Now imagine the difference between a 50mm lens and a 64mm lens!
How can you possibly fit a 50mm lens in the lens mount of a 64mm lens while keeping the focussing mechanism adequate between 1m and infinity?
I am at a loss for an explanation.

Roland


 

I think what was being referred to here was a lens mount design based on that for a Mikro Summar as used in the Ur Leica, except that one was 42 mm (correct me if I am wrong) rather than 64mm. https://www.collectcamera.com/en-us/products/product/leitz-micro-summar-lenses-24mm-42mm-and-64mm-5749 I have the 42mm Mikro Summar (version from c 1912)  and I have often wondered how it might be fitted onto an LTM or M Leica with a focus mount. I have been able to use it via an adapter using a bellows, of course. Barnack developed something very important here and that was focus via a helicoid on a camera, something that had not really existed since the very early days as a bellows had become almost universal. This was one of his biggest breakthroughs.

1 hour ago, Anbaric said:

Maybe Ulf Richter has a contemporary source, or there is some clear precedent for this? 

My experience so far is that the Leitz papers of the period are mainly loose handwritten work notes and it is very difficult to see a written up sequence of what happened when and who was involved. It would be very useful if either Richter or Lagler joined us as they might be able to help us to piece things together into a logical sequence. As Roland pointed out earlier, Barnack kept hand written notes and this is also how he received information and test results on lenses etc from his team. In most cases there is no written out narrative, just figures with cryptic notes beside them. Even the minutes of the famous 1924 'go decision' meeting are not available. 

William 

  • Like 1
Link to post
Share on other sites

There are probably many reasons why a particular newly-developed lens might not have been used.  Besides the Zeiss Tessar patent and discoloring of the external glass surfaces, the glass for the front may have been just too soft and prone to scratches, or one of the glass types may have been discontinued by its maker, or simply that the grinding and polishing of one of the elements in the 4-element Anastigmat may have presented problems.   The 1933 Leitz publication says, (my translation) "When in 1921 the possible production of this camera received increased interest in our factory, the first test specimens were equipped with a 1:3.5 lens which was protected by the Ernst Leitz company via patent 343086 from 1920. Since this lens was only for the first Leica cameras used internally within the factory it was not given a different name".

Either this statement, more than 10 years after the fact, is not entirely correct; or if it is, then all those early test specimens had their lens replaced, early on.

IMO the 1920 4-element Anastigmat is a stepping stone, but also a red herring in trying to understand early Leica history.  Ottmar has already proven for me at least that that lens is now vaporware.  I would be very surprised if an example of it ever turns up.

 

Ed 

Edited by Edward Schwartzreich
wanting to quote paper
Link to post
Share on other sites

Barnack developed something very important here and that was focus via a helicoid on a camera, something that had not really existed since the very early days as a bellows had become almost universal. This was one of his biggest breakthroughs.

William,

The idea of focussing via a helocoid on a hand camera was already embodied in the revolutionary Anschütz focal plane camera of the late 1880s.
In 1913-1914 the challenge for Oskar Barnack was to realise the same idea in a miniature camera with a miniature lens. 

And of course, to use perforated 35mm film instead of glass based dry plates.

The ad below is from 1906. 

Roland

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!

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...