The Pentacon Six System
by TRA

Design Variations, Calculation Dates and Serial Numbers of Carl Zeiss, Jena lenses for the Pentacon Six

Design variations


Zeiss lenses in the Praktisix/Pentacon Six mount were produced during a period of 35 years: from 1956 to 1991.  Over this period of time, various changes were made to the lenses.   Some lenses were re-calculated during that time, but most were not, so there are two principal differences between most lenses produced during that period of time:

a) stylistic or “cosmetic” changes
 
The very first post-war lenses had a mostly metal-colour finish, with a black leather band on the focussing ring.

This 80mm Tessar lens in Praktisix / Pentacon Six mount left the production line on 27th February 1958.

Most Zeiss lenses other than the 1000mm mirror lens had the same design style, so when changes of styling were introduced, they were phased in to all other Zeiss lenses except the mirror lens.

(Meyer-Optik / Görlitz did not follow these style conventions and mostly produced lenses with a black finish during the years that the Praktisix and Pentacon Six were manufactured, though lenses in the early-to-mid 1950s were bright alloy).

When buying any camera with inter-changeable lenses, bear in mind that the lens may not be the one that was on the camera when it was new.  This Praktisix II was manufactured between 1964 and 1966, but the Tessar lens shown here was last produced in the Praktisix mount in February 1958.  It would have been fitted to the original version of the Praktisix.

The makers of the Praktisix decided that the camera would sell better if it had the option of a more prestigious standard lens than the four-element Tessar, although we should not forget that at the time the first Hasselblads were also being supplied in many markets with a Tessar lens.  (However, the Meyer-Optik Primotar continued to be offered as an economical alternative for a number of years.)
 


Tessar 1958
For the Praktisix a change of Zeiss lens on offer was made to the five-element Biometar, which was first produced in the Praktisix mount on 24th March 1959 (earlier versions having been produced for the Rolleiflex and other cameras).  This had the same optical design as the 80mm Planar lens that was being produced by the West German Zeiss factory at about the same time.

The first 80mm Biometars for the Praktisix had the same cosmetic style as the Tessar illustrated above – mostly alloy, with a black leather focussing band. 

However, some of the lenses later in the same production run(!) of 7,000 80mm Biometar lenses introduced a style change: a plastic band with bumps on it was used on the focussing ring instead of the leather band.  The lens illustrated on the right here was part of that first production run.  It rather looks as though the manufacturers used up their stocks of leather bands before starting to use the plastic rings with the bumps – or perhaps the plastic rings were a component that was not ready at the beginning of the production run, a situation that regularly occurred in the post-war years in East Germany.


Biometar 1959
Subsequently, the barrel sections with the distance measurements and the depth-of-field index ring were produced in black, with white numbering for meters and red for feet, and the “bumpy ring”, as I call it, was used for focussing.  The aperture selection ring continued to be plain alloy, with red numbers.  The very front ring, with the thread to accept filters, also now had a black front edge.

Pentacon Six brochures produced in 1966 and 1967 show lenses with this finish.  However, this particular lens completed the final stage of manufacture on 17th December 1964, and it would probably  have been supplied on a late Praktisix IIA.

One 1968 brochure also shows lenses with this finish, but the lenses must have been taken from earlier production runs, as the mostly-black lens style with a leather band on the focussing ring had entered production in 1965 – see the next section.

This “bumpy ring” was not very reliable.  With rough handling it could easily crack or work loose, so a return was made to a leather band.


Biometar 1964
The 80mm Biometar illustrated here was completed on 29th November 1965.  It may well have been supplied on this Praktisix IIA body.

For this lens the aperture index ring, the focussing ring and the whole of the filter ring were black.  The aperture selection ring was still plain metal with red numbers.

 The next version of the lens – the famous “zebra” design –  was in production by 1967.


Biometar 1965
The so-called “zebra” lenses had a finish that was mostly black, but with plain metal stripes and front edge on the focussing and aperture rings.  (This was approximately 1967-74.)  This 80mm Biometar was completed on 28 September 1971.

  Each time there was a style change, all the lenses within the range were made to the same cosmetic style.
This 65mm Flektogon was completed on 27 May 1967.  However, the changes were gradual (presumably as parts were used up).  See more about this below.


Biometar 1971
After that the lenses were designed all in black, with a diamond or pyramid-shaped pattern on the focussing ring, but a bright metal front edge to the focussing ring.

Note that – as with previous versions of the lens – the feet (red) and metres (white) distance markings continue to be shown on this lens, which was finished on 19th July 1978.


Biometar 1978
Later, various changes of style of the all-black lenses were introduced.  This is one of the last Biometars produced.  It was completed on 29 September 1989, about six weeks before the fall of the Berlin Wall, which led to dramatic economic as well as political changes in the GDR.

Note the lack of feet markings – export to the U.K. and the USA had long since been abandoned.

Notice also that the front edge of the focussing ring is now black.


Biometar 1989
There was of course also a subsequent version of the 80mm Biometar, but this was not in any sort of Zeiss design; it had the design of the Schneider-Kreuznach lenses that were supplied for the Exakta 66 (1984-2000 version).  You can see pictures of it here.

Note that this is a summary of the main style changes only.  For instance, there were changes of lettering style and size on the lens name ring, and the actual wording used, depending on the intended market.

There were also other changes.  For instance, on the 180mm and 300mm Sonnars, the stop-down lever was replaced with a “switch” that could be moved between open-aperture and stopped-down positions, and the barrel of the 300mm Sonnar was re-designed to make it slightly smaller and lighter.
 
As a further example, here are two 120mm Biometar lenses.
The one on the left has a number in the ten millions and was completed on 31st October 1978.
The one on the right has a five-digit serial number in the ten thousands and was completed on 27th April 1990.
It is one of the last lenses manufactured by Carl Zeiss Jena before all the changes that occurred in 1990 and subsequently.

There are two main differences between the two lenses:
1)  As with the 80mm Biometars above, the the front edge of the focussing ring on the 1978 lens has a shiny polished metal finish, while on the 1990 lens this edge is black.
2)  If you look carefully, you will just be able to see that the 1978 lens has distances marked in metres (in white) and in feet (in red), while the 1990 lens only has distances in meters.

Those who look at every detail will observe that the placing of the letters “MC” is different on the two lenses.  In fact, the lettering on the front ring of the newer lens is also larger and less spaced-out.

The two lenses have projected images of the window opposite them onto the background (naturally, upside-down!).

 

[2_120bms.jpg]
Phasing-in of style changes

As indicated above, constant shortages were a factor in life in post-war Germany (and in East Germany right up to the end, in 1989!).  Components, once manufactured, had to be used, and this, of course led to the gradual introduction of changes across the lens range.  This is a source of multiple small variations in the details of the lenses that were produced.  (This is fascinating – or frustrating! – for lens collectors!)

This can be seen in the illustrations of equipment in much of the manufacturer’s literature.  The image to the right is taken from a 1964 Praktisix II brochure.  In it, the 80mm Biometar and the 65mm Flektogon have the plain alloy finish with the leather focussing band (as in the first image above), while the 50mm Flektogon, the 120mm Biometar and the 180mm Sonnar have black rings for the focussing and aperture markings, with the bumpy black plastic focussing ring and light alloy aperture rings (as in the third image above).

The lens on the far right is the 300mm f/4.5 Tele-Megor from Meyer-Optik, who did not follow the Zeiss style conventions.

The 1000mm Zeiss mirror lens almost never followed the Zeiss style used with other lenses.  It was generally a pale grey, sometimes with a hint of cream or green.  In this image, it has a light shade of blue, which presumably reproduces correctly the colour of the original lens photographed.  Only in the very last years was an all-black version available.

Note that at the time that this brochure was prepared, three East German lenses that subsequently became part of the standard offering for the Pentacon Six had not yet started production: the 300mm f/4 Zeiss Sonnar, the 500mm f/5.6 Meyer Orestegor and the 300mm f/4 Meyer Orestegor.

This particular brochure was designed for the United States, where there were at the time court cases, initiated by West German Zeiss, to try to prevent Carl Zeiss Jena from using the Zeiss name and other Zeiss lens names such as “Biometar” and “Sonnar”.  It is for this reason that the manufacturer is merely referred to as “Jena”, and the lenses have the names “Bm” and “S”, respectively.  “Flektogon” had never been used by West German Zeiss, who used the name “Distagon” for its wide-angle lenses, which is why the Flektogon name does appear in this brochure.

You can read more about these legal desputes, and how they were resolved, here.



A page from a 1964 Praktisix II brochure/catalogue

b) Single coating or multi-coating

Starting in 1976, Carl Zeiss gradually introduced multi-coating for all its lenses.  This is easy to identify, as multi-coated lenses are marked “MC”.  In the early years of the change, these letters were in red paint, but from about 1980 onwards, the letters “MC” were usually in white paint.

If you see two equivalent lenses, but one is single-coated and the other is multi-coated, I would of course recommend the multi-coated lens, which will be newer.

c) Optical Re-calculation of lenses

Various lenses with the Praktisix/Pentacon Six mount were optically re-calculated over the period of many decades during which they were produced.  One example is the 80mm Biometar.  The original version of this lens in the Praktisix/Pentacon Six mount was calculated on 5th June 1956, although the first batch of this lens in what was at the time called the Praktisix mount was not produced until 24th March 1959.  Over the following 30 years, almost all of the 80mm Biometars that were produced used the 1956 calculation.  However, on 31st October 1979 the 80mm Biometar was re-calculated.  Nevertheless, even after this date most of the 80mm Biometars produced were to the original calculation.  Ten years later, on 29th March 1989, just one batch of 6,000 80mm Biometars was produced using the new calculation.  The serial numbers of that batch are 42,001 – 48,000

Here is a summary of the design dates of Carl Zeiss lenses in the Praktisix/Pentacon Six mount.  However, as will be obvious from the preceding paragraph, sometimes even after a new design was calculated, the lens continued to be manufactured to the previous design, and sometimes even after batches made to the new design were produced, some subsequent batches were made to the previous optical design.
 

Lens
Optical Calculation date(s)
50mm Flektogon 25 March 1958
27 May 1966
65mm Flektogon 6 January 1950
80mm Biometar 5 June 1956
31 October 1979
80mm Tessar (1) 7 July 1950
120mm Biometar 30 July 1956
180mm Sonnar (2) 14 February 1959
4 July 1966
300mm Sonnar 19 August 1963
11 July 1974

(1)  The Tessar had of course existed for decades before a version was calculated for use with the German post-war medium format cameras.
(2)  It is of course well-known that this lens was first calculated and designed for the 1936 Berlin Olympics, where it was used on a 35mm Contax rangefinder camera.  However, the first version that was manufactured in the Praktisix/Pentacon Six mount was the February 1959 re-calculation.

Reasons for re-calculating lenses

It should be borne in mind that there could be various motives behind a re-calculation, and one must not automatically assume that a newer calculation must be optically better; the purpose of the re-calculation might be to reduce weight, as in the case of the 300mm Sonnar.

Changes in other requirements could also lead to design changes.  Thus, for example, the first design of the two Sonnars for the Praktisix/Pentacon Six incorporated automatic micro-adjustment of the diaphragm diameter as one focussed closer, to compensate for the slight reduction in light transmission to the film as the barrel length was increased by focussing closer.  (As one focussed closer, the diaphragm opened progressively.)  Two factors led to the removal of this feature when the lenses were re-designed:

Other motives might include reducing manufacturing costs or making manufacture, assembly or servicing easier.

Optically, all of the Carl Zeiss lenses are excellent.  The mechanical condition depends on whether the lens has been looked after or badly-treated by a previous owner – for instance, if it has been dropped or taken apart by someone who does not understand lenses.

Serial numbers

Fortunately, it is possible with the help of the serial number to date most of the lenses that Carl Zeiss, Jena produced and there is a book that gives detailed information on the date of design and manufacture of Carl Zeiss lenses, based on the serial number.  This book is Dr Hartmut Thiele’s “Fabrikationsbuch Photooptik II Carl Zeiss Jena”, which lists most Carl Zeiss Jena lenses manufactured between 1927 and 1991.  I recommend this book to anyone who wants to go into the details of Carl Zeiss Jena serial numbers.  The book costs about 50 Euros.

Batches of serial numbers were apparently assigned to the production department in Carl Zeiss, Jena in sequence order.  i.e., if the last lens in the previous batch of lenses had the number 8,000,000, the first lens in the next batch would be given the number 8,000,001.  However, sometimes the production department did not make the batches in the same order as the serial-number blocks that had been assigned to them.  Thus, for example, a batch of 5,000 80mm Biometars was assigned the serial-number block 10,890,988 – 10,895,987 and this batch was finished on 2nd September 1980.  The previous block of 5,000 serial numbers (10,885,988 – 10,890,987) had also been assigned to a batch of 80mm Biometars, but this batch was not completed until six months later, on 28th February 1981.  However, in spite of details of this nature, serial numbers are a good guide to the age of a lens.

In the example above, I have added commas here, to make the numbers easier to read, but no commas, full stops or spaces were used when the serial number was engraved on the lens, unlike the practice of Schneider-Kreuznach, who put spaces where I have put commas.

By mid 1980, Carl Zeiss had reached the serial number 10,982,372 (nearly 11 million).  It then decided to start the serial numbers anew, apparently beginning at 1,0001 (although there are very small numbers of lenses produced in the 1980’s with lower numbers than this).  So most lenses made between about mid 1980 and 1991 had four or five-digit serial numbers and are therefore the newest lenses.  (You can see from the example given above that some of the lenses with serial numbers in the ten millions were in fact not completed until early in 1981.)



Hartmut Thiele’s book on Carl Zeiss Jena lenses

A wide range of Carl Zeiss Jena lenses in Praktisix/Pentacon Six mount are illustrated and tested in the Lens Test section of this website.  To go to the lens test section, click here.

To see some information on camera body variations and dates, see here.

To go on to the next lens data section, click below.
How the country of origin of East German lenses was specified

To go back to the beginning of the Lens Data section, click below and then choose the range of lenses that you want to read about.

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© TRA  January 2010.
Latest revision: February 2017