100 years Null-Serie

[Roland Zwiers]

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You mention that Lehr obtained #116.

In the right column (with loaner cameras) one can see Lehr and 116

It is the only loaner camera in the right column with the number specified.
But the number is underlined, which is also an exception on page 115.

And it is also striking that #116 is not mentioned in the deliverybook 'Kamera'.
This may be because loaner cameras in general were not 'delivered', like the cameras in the central column of page 115, but loaned, like the other Leihkameras in the fourth column?

So many questions!!

[pedaes]

18 minutes ago, Roland Zwiers said:

So many questions!!

I am sure you will get there!

Thank you and @UliWer

[Roland Zwiers]

Pedaes,

Thank you for your kind words.
But in order to arrive at plausible answers, one needs at least access to known primary sources.

For me the most important known primary sources in this early period are:

- The Werkstattbuch of Oskar Barnack

- The deliverybook 'Kamera', where I would like to consult the first 2500 entries or so.

- The contact prints of the negatives of Ernst Leitz II from his June 1914 visit to the USA

- An overview of the pictures made by Oskar Barnack in the period 1913-1925 or so. 

Without these primary sources it is not easy to make meaningful progress.

 

Roland

 

 

  

 

[sandro]

Roland, be very cautious when using Paul Wolff as a source, since he wasn't always accurate in remembering things! You mentioned Paul Wolff in a hypothesis, based on a photo allegedly from 1924. You are refferring to his Meine Erfahrungen mit der Leica, of which the first edition is from 1934. In the second edition of 1939 that you refer to he shows a sequence of images, the first of which supposedly dates from 1924. Is this the photo you meant?

Interestingly, in the first edition of 1934, he has a similar sequence of photos to show his progress, but these are different photos and the first one supposedly dated from 1925! 

In 1941, in his contribution to the Festschrift for Ernst Leitz, he mentioned that Barnack was not a photographer, but we know that Barnack did take photos. Wolff also claimed that he seriously warned Barnack about the possible future of the miniature camera, thereby perhaps claiming some sort of position for himself both in his freindship with Barnack and in the history of the Leica. Also see the article by Ed Schwartzreich about this in  Viewfinder vol. 47, issue 4, with English translation of the German text of Wolff's 1941 article, continued in Viewfinder vol. 48, issue 1.

As regards the various kinds of fabric mentioned, it seems that Barnack was experimenting with different materials for the shutter: some kind of silk, Kodak cloth and rubber samples. 

Lex

[Roland Zwiers]

UliWer,

One loose end from the 2023 discussion is my working hypothesis that the Null-Serie could have been forwarded by one or two years.
This was possible by selecting a 1:4,5 Zeiss Tessar instead of asking Max Berek to create a 1:3,5 f=50mm Anastigmat.

This is a big discussion as well and I can not finish this in this post.
Presenting the evidence is time consuming.

In my analysis the Tessar design of 1902 already allowed for a 1:6,3 Tessar with a focal lenght of f=55mm.
These Tessars were used between 1902 and 1907 on the Verascope stereo cameras with negatives of 4x4cm.
For this size the f=55mm Tessars had an angle of view of about 55 degrees.
These cameras had alternative f=54mm to f=60mm lenses as well, but the Tessar was the pick of the pack.
It seems that after 1902 the Tessar was even preferred to the famous 1:6,8 Goerz Dagor.

Now in 1907 the original Tessar design was modified in two ways.
There was a very fast alternative 1:3,5 with an angle of view of 35 degrees.
And a relatively fast alternative 1:4,5 with an angle of view of 55 degrees.
Both these designs could be scaled to miniature sizes.
This happened with the 1:3,5 Tessar for f=50mm as Kino-Tessar for the 18x24mm format.
Oskar Barnack would use this lens on his movie camera of 1913.

In 1908 the 1:4,5 f=55mm Tessar was the new top of the bill lens for the 4x4cm [45x107mm] Verascope.
This occured while Oskar Barnack was employed at Zeiss Palmos!
In his position at the camera assembly department he may even have advised the producer of the Verascope on the suitability of the new 1:4,5 Tessar!

Now the 1:4,5 was scaled to the f=55mm size because there was a customer for the 4x4 cm negative size.
In fact many customers, as the 45x107mm Verascope was widely copied by other manufacturers.
But theoretically, the 1;4,5 Tessar design could have been scaled back even more to e.g. 42, 45 or 50mm.
Zeiss did not do so because in the period 1907-1923 there was no demand whatsoever for a 1;4,5 Tessar that covered a negative of 24x36mm.

Now in 1913-1914 Oskar Barnack could have selected a 1:4,5 f=55mm Tessar for his Ur-Leica.
We know that he did not do so.  
why not?
Possibly because he preferred the wider angle of the 1:4,5 f=42mm Mikro Summar.
Even though this Mikro-Summer was not corrected for taking pictures at infinity.

But now we arrive in 1919-1920.
Ernst Leitz II and Oskar Barnack need a better lens for the new prototype.
In my analysis the 1:4,5 f=55mm Tessar was still available.
{The 45x107mm Verascope was still in production!]
Ernst Leitz II could even have played safe by asking Max Berek to scale the 1:4,5 Tessar design to f=42mm.
This would have been low risk, but Leitz would have had to pay a licence to Zeiss for maybe two or three years.
That is, the remaining period of the Tessar patent.

We know that Ernst Leitz II did not do so: he asked Max Berek to aim at an 1:3,5 f=50mm Anastigmat.
This was a very innovative venture but also high risk.
In my analysis, based on the observations of Ottmar Michaeli, this first 1:3,5 f=50mm Anastigmat was not succesful.
It is plausible that there was a problem with the outer surfaces of the lens.
Was it vulnarable to scratches or to atmospheric influences (discolouring)? 
We don't know.
we only know that the two remaining cameras for which this lens was designed have a later 1:3,5 f=50mm Anastigmat.
So at one stage the original 1:3,5 f=50mm anastigmats have been removed and replaced.

So in my working hypothesis, playing safe in 1920 by selecting a 1:4,5 Tessar design could have speeded up the introduction of the Null-Serie.
And Max Berek could still have continued with his 1:3,5 project.

That does not mean that an earlier Null-Serie would have been equally succesfull.
In 1921 there was no hyper inflation yet, but there may have been other complications. 
My working hypothesis, the Null-Serie could have been introduced one or two years earlier, is a counter factual based on curiosity.

The Leica was a big investment risk.
Knut Kühn-Leitz wrote a fascinating book on this subject.
So why would Ernst Leitz II have increased the investment risk by not playing safe?

 

Roland

 

  

 
 

 

 

 

 

 

 

 

   

[Roland Zwiers]

3 minutes ago, sandro said:

Roland, be very cautious when using Paul Wolff as a source, since he wasn't always accurate in remembering things! You mentioned Paul Wolff in a hypothesis, based on a photo allegedly from 1924. You are refferring to his Meine Erfahrungen mit der Leica, of which the first edition is from 1934. In the second edition of 1939 that you refer to he shows a sequence of images, the first of which supposedly dates from 1924. Is this the photo you meant?

Interestingly, in the first edition of 1934, he has a similar sequence of photos to show his progress, but these are different photos and the first one supposedly dated from 1925! 

In 1941, in his contribution to the Festschrift for Ernst Leitz, he mentioned that Barnack was not a photographer, but we know that Barnack did take photos. Wolff also claimed that he seriously warned Barnack about the possible future of the miniature camera, thereby perhaps claiming some sort of position for himself both in his freindship with Barnack and in the history of the Leica. Also see the article by Ed Schwartzreich about this in  Viewfinder vol. 47, issue 4, with English translation of the German text of Wolff's 1941 article, continued in Viewfinder vol. 48, issue 1.

As regards the various kinds of fabric mentioned, it seems that Barnack was experimenting with different materials for the shutter: some kind of silk, Kodak cloth and rubber samples. 

Lex

Lex,

Thank you for your reply.
I agree completely with your observations.
One has to interpret the observations of Dr Paul Wolff in context.
This is a very big subject as well!

E.G. Oskar Barnack obviously was a keen amateur photographer!
What amateurs of 1905 would still carry a heavy 13x18 outfit?
In 1905 most amateurs were happy with a you-press-the-button-we-do-the-rest Kodak.
This is the subject of another article.

Roland

 

[sandro]

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Can the name of Freund that was mentioned twice be connected to the father of Gisèle Freund, who was given a Leica by her father in 1928 when she finished high school?

According to Hans-Michael Koetzle Paul Wolff got his first Leica early 1926.

Lex

[UliWer]

3 hours ago, Roland Zwiers said:

And it is also striking that #116 is not mentioned in the deliverybook 'Kamera'.
This may be because loaner cameras in general were not 'delivered', like the cameras in the central column of page 115, but loaned, like the other Leihkameras in the fourth column?

Yes. There is an obvious distinction between „Lieferung“ (delivery) and „Leihkamera“ (camera on loan). By delivering a camera in this sense Leitz lost the ownership, by loan they remained owners. I think the delivery register was restricted  to real „deliveries“ in this sense. Therefore Barnack indicates when a camera on loan was sold (in the case of „Freund, Berlin“). This was probably important for the inventory stocktaking, which every commercial firm has to do annually. The delivered cameras didn‘t belong to the factory’s inventory any more, while the loaned cameras still did.

Though they didn‘t act as a usual producers who deliver their items to sell them at this time. The main aim was to get a feedback from people who tested them. If the assumption is true that Barnack had some cameras in his cupboard which weren‘t delivered but just loaned, they must have been treated outside the delivery register.

Perhaps most important: you attach much importance to the massive inflation which took place at this time. This might have had an influence on how people  acted. Though they still had their jobs and wanted to keep them. Therefore I believe that even though inflation meant a lot of grievances for many people it didn‘t change the way they did their jobs. I think it is important to consider the status the camera had at this time: it wasn‘t an official Leitz product, but more or less a private „hobby“ of Oskar Barnack. Of course he was allowed and endorsed  by Ernst Leitz to follow his hobby. Though other people at Leitz were against it (literally told so by Ernst Leitz in a radio interview after the war). Therefore it was called „Barnack Camera“ before it was branded „Leca“ and then „Leica“. So it is plausible to assume that at least some of the loans were under the discretion of Barnack alone. Though Baranack was no accountant clerk for whom bookkeeping was the only aim. He wanted results and didn‘t mind so much how he got them. In my view that‘s the real reason for he rather chaotic bookkeeping of cameras which went on loan. He even may have started the whole bookkeeping long after the fact, which could explain the reversed chronology.  

Edited May 15 by UliWer

[UliWer]

1 hour ago, Roland Zwiers said:

One loose end from the 2023 discussion is my working hypothesis that the Null-Serie could have been forwarded by one or two years.
This was possible by selecting a 1:4,5 Zeiss Tessar instead of asking Max Berek to create a 1:3,5 f=50mm Anastigmat.

This is a big discussion as well and I can not finish this in this post.

…

Roland, I don‘t agree with you that a Tessar lens might have been used earlier.

When Zeiss presented their 1:3.5/5cm for the Contax they wrote, that the Tessar design (4 lenses in three groups) was a very traditional one but that the lens was newly designed for the 35mm format. Why would they need a new design if they already had one in their cupboard? And more important: how can you redesign a traditional lens? You need new glass.

Barnack and Berek definded the demands a lens should fulfill to be used for a 35mm camera. They tried the 1.3.5/50mm Kino-Tessar from 1913 and it didn’t meet the demands.  Berek had patented a new lens with 4 lenses in 3 groups already in 1920  which had the novelty that the second lens was „floating“ on the axis. This „floating element“ lens was never realised. So Berek opted for the 5 element design in 3 groups with 3 lenses glued together which was the „Anastigmat“ or „Elmax“ for the very early cameras. Of course the production of this lens was complicated and expensive.

The change came when the „Sendlinger Glaswerk“ of Goerz made new glasses with low dispersion. This was in 1925 which immediately allowed Berek to design the Elmar with 4 lenses in 3 groups, which met the demands for the Leica (even if the older Anastigmat with 5 lenses may have been better when you look at the results from the remake of the Leica „0-Serie“ of 2000) Zeiss used the same glass - or equal glass of own production - for their new Tessar for the Contax (the design dates from July 1929).

As this glass wasn‘t available before there was no chance to use a Tessar which met the demands definded for the Leica.

Edited May 15 by UliWer

[Roland Zwiers]

1 hour ago, sandro said:

Can the name of Freund that was mentioned twice be connected to the father of Gisèle Freund, who was given a Leica by her father in 1928 when she finished high school?

According to Hans-Michael Koetzle Paul Wolff got his first Leica early 1926.

Lex

Lex,

This Dr Paul Wolff legend about winning a leica in 1926 is a legend that he launched himself in 1937.
He did not win this camera! 
It was payment in kind for organising this 1926 exhibition in his new hometown Frankfurt a/M.
It was not his first Leica either.
I have covered this subject extensively earlier in this thread.

It just shows how right you are.
When quoting Dr Paul Wolff one has to be extremely careful with the context.
This is the subject for another article. 

Roland

[Roland Zwiers]

21 minutes ago, UliWer said:

Roland, I don‘t agree with you that a Tessar lens might have been used earlier.

When Zeiss presented their 1:3.5/5cm for the Contax they wrote, that the Tessar design (4 lenses in three groups) was a very traditional one but that the lens was newly designed for the 35mm format. Why would they need a new design if they already had one in their cupboard? And more important: how can you redesign a traditional lens? You need new glass.

Barnack and Berek definded the demands a lens should fulfill to be used for a 35mm camera. They tried the 1.3.5/50mm Kino-Tessar from 1913 and it didn’t meet the demands.  Berek had patented a new lens with 4 lenses in 3 groups already in 1920  which had the novelty that the second lens was „floating“ on the axis. This „floating element“ lens was never realised. So Berek opted for the 5 element design in 3 groups with 3 lenses glued together which was the „Anastigmat“ or „Elmax“ for the very early cameras. Of course the production of this lens was complicated and expensive.

The change came when the „Sendlinger Glaswerk“ of Goerz made new glasses with low dispersion. This was in 1925 which immediately allowed Berek to design the Elmar with 4 lenses in 3 groups, which met the demands for the Leica (even if the older Anastigmat with 5 lenses may have been better when you look at the results from the remake of the Leica „0-Serie“ of 2000) Zeiss used the same glass - or equal glass of own production - for their new Tessar for the Contax (the design dates from July 1929).

As this glass wasn‘t available before there was no chance to use a Tessar which met the demands definded for the Leica.

UliWer: When Zeiss presented their 1:3.5/5cm for the Contax they wrote, that the Tessar design (4 lenses in three groups) was a very traditional one but that the lens was newly designed for the 35mm format. Why would they need a new design if they already had one in their cupboard? And more important: how can you redesign a traditional lens? You need new glass.

UliWer,

I think we agree more than you think 🙂
In 1920 designing a 1:3,5 four-element anastigmat covering an angle of 55 degrees was an enourmous endeavour.
Zeiss did not do this, Max Berek was aiming at something very high!
And so his first attempt was not succesful.

You are also right that for the second attempt Berek needed five lens-elements instead of four.
Why?
Because with the old glass he needed the extra lens element so as to arrive at a good correction.
The 5-element lens was a good lens, tested on the Null-Serie (!), but expensive to make.
 

At the third attempt new glass made it possible to aim at four lens elements again;
this new glass first came from Schott Jena and later from the Sendlinger Glaswerk. 

The step from the 1:6,3 Tessar of 1902 to the 1:4,5 Tessar (for the angle of 55 degrees) required a big design change!
The same happened again when Zeiss needed to create a 1:3,5 Tessar (with an angle of 45 degrees) for the Contax.

The discussion on Elmar-Tessar seems to have started with negative Zeiss publicity on the Elmar.
I have not yet been able to find this primary source.
If you have it, please share it with me.
Leitz replies to this negative publicity by publishing a reply in Die Leica.
Ed Schwartzreich and me have discussed this publication in detail.

This is also a ubject fora separate article.

I happened to have a free day today 🙂
But I must make urgent preparations for tomorrow.
Next week I can come back on this conversation again.
Thank you for your respectful and knowledgable questioning of my working hypotheses.

 

Roland
 

 

 

 

 

 

[derleicaman]

6 hours ago, Roland Zwiers said:

I discussed this page before in my research presentation.
One can see three columns.

The left column has 4 names.

The middle column has many names; I assume that these people received an Ur-Leica more or less as a gift.
[which does not exclude the possibility that some of these still returned the Ur-Leica after use.]

The right column explicitly mentions: Leihkameras.

So I assume that the recipients in this column were expected to return the Ur-Leica anyhow. 
Oskar Barnack could have stored these Leihkameras in a special cubboard.

In my working hypothesis Dr Paul Wolff was one of the recipients of such a Leihkamera.
In Meine Erfahrungen mit Die Leica (1939) he published a Leica picture that he took in 1924.
He uses this 1924 picture so as to show his progress over a period of 15 years.

Roland, do you mean to say Null-Serie cameras? There were only 3 of the Ur-Leica of maybe only 2 that I know of.

[Roland Zwiers]

Bill,

On page 115 of the Werkstattbuch we see Null-Serie cameras.
These are later prototypes that the ones from, say, 1914-1921.

I can discuss this now, I have to prepare for tomorrow.
But you already have my manuscript and this describes the full sequence of prototypes between M875 and the Null-Serie.

 

Roland

 

 

 

[beoon]

On 5/10/2025 at 4:20 PM, derleicaman said:

One of the members here on the forum has shared with me that 109 was sold to the Eastman House museum in 1951. The owner at that time lived in England. I will wait for our member here to share his information if he so wishes. Now the question might be, what was the story of this camera from when it was shipped to the Leitz Agency in Berlin to 1951, when it was sold to Eastman House.

I love these mysteries!

Hi Bill, Roland & William

Nice to see this thread alive again, regarding Null Series No 109, here is the detail of how it ended up in the George Eastman museum in Rochester

On the 4th September 1951 Kodak Limited (UK) purchased No 109 from an English owner called Mr Walsh for the sum of $100.

At some point it was shipped to George Eastman Museum in Rochester.

$100 was a reasonable sum, given that the camera was only 28 years old at the time of purchase.

How the camera ended up in the possession of Mr Walsh in England prior to 1951 has yet to be established.

No 109 is still in the George Eastman museum and is notable for being only one of three with the original folding viewfinder (119 and 122 being the others)

No 110 is owned by the JCII museum in Japan

Regards

Alan

[beoon]

9 hours ago, jerzy said:

indeed, from August 1929 Leica was equipped with curtains from Kodak. This replaced earlier 3 layer curtains (fabric-rubber-fabric).

Jerzy,

I also believe that E Leitz Inc NY suggested using a Graflex rubberised shutter cloth to the factory and supplied a sample.

The factory ordered 200 yards of the Graflex rubberised cloth (prior to 1929)

Regards

Alan

[beoon]

Roland,

Following my article in Viewfinder magazine No 57-1 regarding Professor Klute using Null Series No 114, I stated that Null Series user feedback was very rare.

No sooner had that magazine went to print and some more Null Series user feedback came to light (feedback from a Leitz sales representative in September 1923).

This will form an update article for Viewfinder magazine (at some point in the future).

Regards

Alan

 

[UliWer]

3 hours ago, Roland Zwiers said:

I have not yet been able to find this primary source.
If you have it, please share it with me.

The statement by Zeiss about the 1:3.5/5cm Tessar for the Contax comes from a brochure: "Die zehn Objektive der Contax". It is undated, though it must have been published in the first years of the Contax.

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!

 

On p.24f they deal with the Tessar 1:3,5 f=5cm. The sentence after the semicolon on p.25: "...;denn auch das Contax-Tessar stellt - obwohl doch Tessare im allgemeinen bekannt waren und vielleicht als eine abgeschlossene Konstruktion gelten konnten - eine Sonderkonstruktion dar, die speziell dem Format 24x36mm angepasst ist." 

My translation: "..., even though Tessar lenses were well known and perhaps could be regarded as a completed design, the Contax-Tessar is a special design, explicitly adapted to the format of 24X36mm." (There is probably an English version of this brochure which has the official translation).

As they make a point of calling  the Contax-Tessar a "special" design ("Sonderkonstruktion") for the new format they also state that there older Tessar versions were not fulfilling the demands. The two last sentences on the page before explain: "It is rarely necessary to stop down the lens, as the Tessar even fully opened draws sharp into the outmost corners. Even though it seems to be self-evident, not all lenses have this feature; though with Contax lenses it is fulfilled with absolute guarantee; ..." (follow the statements I quoted above).

 

Edited May 15 by UliWer

[Roland Zwiers]

10 hours ago, Roland Zwiers said:

UliWer: When Zeiss presented their 1:3.5/5cm for the Contax they wrote, that the Tessar design (4 lenses in three groups) was a very traditional one but that the lens was newly designed for the 35mm format. Why would they need a new design if they already had one in their cupboard? And more important: how can you redesign a traditional lens? You need new glass.

UliWer,

I think we agree more than you think 🙂
In 1920 designing a 1:3,5 four-element anastigmat covering an angle of 55 degrees was an enourmous endeavour.
Zeiss did not do this, Max Berek was aiming at something very high!
And so his first attempt was not succesful.

You are also right that for the second attempt Berek needed five lens-elements instead of four.
Why?
Because with the old glass he needed the extra lens element so as to arrive at a good correction.
The 5-element lens was a good lens, tested on the Null-Serie (!), but expensive to make.
 

At the third attempt new glass made it possible to aim at four lens elements again;
this new glass first came from Schott Jena and later from the Sendlinger Glaswerk. 

The step from the 1:6,3 Tessar of 1902 to the 1:4,5 Tessar (for the angle of 55 degrees) required a big design change!
The same happened again when Zeiss needed to create a 1:3,5 Tessar (with an angle of 45 degrees) for the Contax.

The discussion on Elmar-Tessar seems to have started with negative Zeiss publicity on the Elmar.
I have not yet been able to find this primary source.
If you have it, please share it with me.
Leitz replies to this negative publicity by publishing a reply in Die Leica.
Ed Schwartzreich and me have discussed this publication in detail.

This is also a ubject fora separate article.

I happened to have a free day today 🙂
But I must make urgent preparations for tomorrow.
Next week I can come back on this conversation again.
Thank you for your respectful and knowledgable questioning of my working hypotheses.

 

Roland
 

 Roland: At the third attempt new glass made it possible to aim at four lens elements again;
this new glass first came from Schott Jena and later from the Sendlinger Glaswerk.

 

10 hours ago, Roland Zwiers said:

Roland: At the third attempt new glass made it possible to aim at four lens elements again;
this new glass first came from Schott Jena and later from the Sendlinger Glaswerk.

Sorry, here I typed in haste.

The new glass originally came from the Goerz Sendlinger Glaswerk.
When this Glaswerk was closed dow as a result of the Zeiss Ikon merger, Leitz could obtain similar new glass from Schott Jena. 

This is disussed in detail in the Leitz reply to the Zeiss accusation ('The Elmar is a Tessar copy") in Die Leica.

Roland

 

 

 

 

[Roland Zwiers]

8 hours ago, beoon said:

Jerzy,

I also believe that E Leitz Inc NY suggested using a Graflex rubberised shutter cloth to the factory and supplied a sample.

The factory ordered 200 yards of the Graflex rubberised cloth (prior to 1929)

Regards

Alan

Alan,

 

Thank you for this relevant information.

If Oskar Barnack refers to this in his work notes (Werkstattbuch) then the book can only have been finalized around 1929.
This is later than I expected.

It again shows how important it is to have access to the complete manuscript.

 

Roland

 

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[Roland Zwiers]

8 hours ago, beoon said:

Roland,

Following my article in Viewfinder magazine No 57-1 regarding Professor Klute using Null Series No 114, I stated that Null Series user feedback was very rare.

No sooner had that magazine went to print and some more Null Series user feedback came to light (feedback from a Leitz sales representative in September 1923).

This will form an update article for Viewfinder magazine (at some point in the future).

Regards

Alan

 

Alan,

You are absolutely right that feedback from Null-Serie users is very rare.
So I really appreciate your work on Prof. Klute!

I have the 1923 Prof. Klute books in my collection and one can see that the Null-Serie Leica pictures are of poor quality.
Still they serve the purpose.

Because of the Null-Serie Leica he must have been able to take hundreds of pictures without carrying too much weight.
Because of the  fast 1:3,5 lens he could take pictures in the early morning and in the late afternoon.
For his purpose these were decisive advantages, even though the pictures were somewhat disappointing when printed to postcard size.

In my working hypothesis Dr Paul Wolff also used a Null-Serie Leica for a 1924 instruction book on ski-ing.
[J. Dahinden, Die Ski-Schule]
The quality of the Dr Paul Wolff  pictures is even more disappointing than the 1923 pictures by Prof. Klute.

So who knows Dr Paul Wolff was ashamed of himself when he compared his very poor results
[which he blamed on the Null-Serie Leica in his feed-back to Oskar Barnack!]
with those of Prof. Klute.

To be continued.
This is a big subject again!

Roland