The great M39 confusion
This name can be confusing because M39 isn't always actually M39, and not all M39 lenses are the same or fit all cameras. In this article I hope to make it clear which is which and which lenses will fit your Leica, or Leica copy, known hereafter as your camera, as this is where the confusion usually is. In the banner picture you see the Paxette, Zenit & Leica. All have 'M39' threads and are not compatible with each other.
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What does M39 mean exactly?
In camera use, it's a lens mount, 39mm diameter X 1mm DIN. The size was introduced on Soviet Leica copies in the 1930s and carried on right into the 1980s. Is Leica screw thread M39? No, the Leica screw thread mount is an Imperial size of 26 TPI (Turns or threads per inch), while the mount is 39mm wide. This is called LTM (Leica Thread Mount). This is a legacy from Leitz's microscope days where all lens and tube fittings were imperial. |
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The LTM thread pitch is approximately 0.977mm, close enough to 1mm that most M39 lenses will fit. All cameras, apart from the Soviet ones, are LTM. The terms LTM and M39 are often used interchangeably.
So on to the confusion.
Leica made their standard flange focal distance, FFD, a standard 28.8mm. This is the distance between the lens mount and the film plane, it is a common standard with all Leicas, Zorkis, FEDs and Japanese brands such as Canon, Nicca, Tanack etc.
(Some really early Leicas and Feds had slightly differing FFDs but they're extremely rare and the lenses are even rarer. Every post-war camera has 28.8mm) But not every M39 lens has a 28.8mm FFD and this is the problem. These are the most common types of M39/LTM mount that will NOT work on your camera (and their alternative names):
Paxette (B39 or BM39)
Zenit (Z39 or ZM39)
Chaika (M39)
What are they?
OK, I've explained LTM above.
Paxette (B39). These are lenses made for the German Braun Paxette and DeJur D-series cameras. They have the same 26TPI screw thread and many of the lens range have rangefinder couplings so they can be confusing unless you know which they are. The B39 has an 44mm FFD. Longer than Leica.
Zenit (Z39). Zenit was a 35mm SLR camera based on a Zorki, which retained the M39 lens mount at first then changed to the more usual M42 lens mount. The Z39 had a 45.2mm FFD. Longer than both Leica and M42
Chaika M39 The 28mm f2.8 Industar-69 lens fitted to the Soviet Chaika camera is a lens designed for half frame and has a shorter, 27.5mm* FFD, shorter than LTM. *approx.
M39 and 26TPI is used elsewhere, here are some more that I know about.
Enlarger lenses are usually 26TPI because back in the 50s or before, enlargers were designed to use your taking lens as a printing lens.
The Great Wall DF series 6x6 SLR uses M39 lenses but although there were several camera models only one lens type was made. They are branded 'Great Wall'.
Leitz Visoflex or PLOOT long focus lenses, are LTM usually sold and priced as such designed to be used with reflex housings.
Novoflex lenses are designed to be used in their various focusing apparatuses: pistol grips, bellows and reflex housings. Again usually sold and priced as such.
Canon EX lenses are designed to be used with the Canon EE and EX SLR. These are front lens groups that will not work on anything other than the particular Canon models (nor will any other M39 lens work on a Canon EX)
Some 19th century plate cameras used 26TPI fittings in 39mm and 42mm but the lenses are usually very short for their focal length, using bellows to make the extension, and made of brass.
So on to the confusion.
Leica made their standard flange focal distance, FFD, a standard 28.8mm. This is the distance between the lens mount and the film plane, it is a common standard with all Leicas, Zorkis, FEDs and Japanese brands such as Canon, Nicca, Tanack etc.
(Some really early Leicas and Feds had slightly differing FFDs but they're extremely rare and the lenses are even rarer. Every post-war camera has 28.8mm) But not every M39 lens has a 28.8mm FFD and this is the problem. These are the most common types of M39/LTM mount that will NOT work on your camera (and their alternative names):
Paxette (B39 or BM39)
Zenit (Z39 or ZM39)
Chaika (M39)
What are they?
OK, I've explained LTM above.
Paxette (B39). These are lenses made for the German Braun Paxette and DeJur D-series cameras. They have the same 26TPI screw thread and many of the lens range have rangefinder couplings so they can be confusing unless you know which they are. The B39 has an 44mm FFD. Longer than Leica.
Zenit (Z39). Zenit was a 35mm SLR camera based on a Zorki, which retained the M39 lens mount at first then changed to the more usual M42 lens mount. The Z39 had a 45.2mm FFD. Longer than both Leica and M42
Chaika M39 The 28mm f2.8 Industar-69 lens fitted to the Soviet Chaika camera is a lens designed for half frame and has a shorter, 27.5mm* FFD, shorter than LTM. *approx.
M39 and 26TPI is used elsewhere, here are some more that I know about.
Enlarger lenses are usually 26TPI because back in the 50s or before, enlargers were designed to use your taking lens as a printing lens.
The Great Wall DF series 6x6 SLR uses M39 lenses but although there were several camera models only one lens type was made. They are branded 'Great Wall'.
Leitz Visoflex or PLOOT long focus lenses, are LTM usually sold and priced as such designed to be used with reflex housings.
Novoflex lenses are designed to be used in their various focusing apparatuses: pistol grips, bellows and reflex housings. Again usually sold and priced as such.
Canon EX lenses are designed to be used with the Canon EE and EX SLR. These are front lens groups that will not work on anything other than the particular Canon models (nor will any other M39 lens work on a Canon EX)
Some 19th century plate cameras used 26TPI fittings in 39mm and 42mm but the lenses are usually very short for their focal length, using bellows to make the extension, and made of brass.
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Let's look at it in more detail
Soviet lenses have names like Jupiter, Industar, Helios etc. There were basically two ranges of 35mm cameras, SLRs and rangefinders, and confusingly some lenses with the same name were made for each system. The most common 'problem' lenses with Leica/Zorki shooters are the Industar-50 50mm f3.5 and the Jupiter-11 135mm f4. You can see from the picture right away that the SLR lenses are shorter, and that the Jupiter 11 is chunkier, earning the nick-name of hand grenade. The Industar 50's rear part can be unscrewed allowing the lens to be used on an SLR. (See my section on adaptors below). The Jupiter 9, 85mm f2 is less common but can be confused too. The Jupiters are usually made in Contax/Kiev fitting too, so watch out for that! |
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Not all Soviet lenses are confusing, here are some that are made for rangefinder cameras. Probably the cheapest wide angle lenses on the market. The Jupiter 12 35mm f2.8 and the Orion 15 28mm f6. Again both also made in Contax/Kiev fitting
The Jupiter 12 is based on the old Zeiss Biogon lens and as you can see the rear element will go almost to the film plane. This is fine on regular Barnacks but be careful when using it on certain other cameras, the metering tab will get in the way on some TTL metering Leica M-series, and the CL series. The Periflex's focusing system gets in the way and the Voigtlander series' sensor is shaded or impacted.
The Orion is a great lens but the f6 aperture makes it not so great in low light.
The Jupiter 12 is based on the old Zeiss Biogon lens and as you can see the rear element will go almost to the film plane. This is fine on regular Barnacks but be careful when using it on certain other cameras, the metering tab will get in the way on some TTL metering Leica M-series, and the CL series. The Periflex's focusing system gets in the way and the Voigtlander series' sensor is shaded or impacted.
The Orion is a great lens but the f6 aperture makes it not so great in low light.
Then there are the 50s
A variety of 50mm lenses are made for the various Soviet cameras, all will work on your camera, though the collapsible ones are to be used with caution on TTL metering models and the Periflex, collapsing them on camera may impact the TTL mechanism.
The Industar range are 4-element Tessar designs, whereas the Jupiter range are 6-element Sonnar designs. Or so I'm told.
The Industar 10, badged 'FED', were made in Ukraine for the FED and Zarya cameras as were the Industar 61LD. Jupiters and the Industar 22 were made for Zorki and Leningrad models.
All Soviet rangefinder M39 lenses have the Zeiss Contax focusing throw, as people online are fond of mentioning. Though very close to the Leica's it is ever so slightly different. Aparrently.
A variety of 50mm lenses are made for the various Soviet cameras, all will work on your camera, though the collapsible ones are to be used with caution on TTL metering models and the Periflex, collapsing them on camera may impact the TTL mechanism.
The Industar range are 4-element Tessar designs, whereas the Jupiter range are 6-element Sonnar designs. Or so I'm told.
The Industar 10, badged 'FED', were made in Ukraine for the FED and Zarya cameras as were the Industar 61LD. Jupiters and the Industar 22 were made for Zorki and Leningrad models.
All Soviet rangefinder M39 lenses have the Zeiss Contax focusing throw, as people online are fond of mentioning. Though very close to the Leica's it is ever so slightly different. Aparrently.
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Braun Paxette. Beware of cheap German lenses There are a wide range of lenses for the Paxette including many 35 or 38mm wide angle lenses which are the most looked at for Barnack users. These are attractive because of their lower price and come from old, respected German manufacturers like Roeschlein, Staeble, Enna, Schacht and others. Sellers, particularly on ebay often advertise these as M39/LTM lenses which is very misleading whether it was intentional or not. Some manufacturers like Staeble make LTM versions, these are very rare, sellers usually know this and price them accordingly at 3-5 times the price of their Paxette equivalent. Staeble versions have the legend: -L- engraved round the front ring. Paxette lenses will screw onto your Leica but will end up upside down as the thread starts in a different position, the rangefinder coupling (if there is one) may even couple with your camera's. But the pictures will be hopelessly out of focus. Check with your favourite lens group or forum if you have any doubt. Links at the bottom. |
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Here are some misleading listings on ebay. All of them representing the lens as suitable for your camera.
Click on each image to see more. |
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The image on 35mm would be almost circular, which if cropped would negate any advantage of the 28mm focal length. The lens has a shorter FFD and will not focus. It is possible to modify the lens to focus, but you are still left with the vignetting and distortion round the edges. This picture was taken at infinity focus at f2.8.
Often sold as a 28mm wide angle lens as the misleading listing here shows. |
The Industar 69 is most commonly sold as a 28mm f2.8 wide angle lens. A very attractive proposition for Leica/Zorki users. But it isn't, this beautiful pancake lens is designed for the Chaika half frame camera.
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Enlarger lenses are usually LTM but won't work on your camera, there is no standard FFD and there is no focusing mechanism, something to look out for when buying lenses. BUT, I bought a lovely Paxette lens, for cheap, advertised as an enlarger lens. So look anyway, you just may find a bargain. A few pictures of other non compatible lenses: Click on each to open.
So, what about adaptors?
You can buy Paxette to M39 adaptors (if you search hard enough) and the extension on the rangefinder version of the Industar 50 will convert Zenit lenses, but neither will have rangefinder coupling so focusing has to be done using the scale. Check out my page on the Human Rangefinder https://www.philip-birch.com/human-rangefinder.html .
You can buy Paxette to M39 adaptors (if you search hard enough) and the extension on the rangefinder version of the Industar 50 will convert Zenit lenses, but neither will have rangefinder coupling so focusing has to be done using the scale. Check out my page on the Human Rangefinder https://www.philip-birch.com/human-rangefinder.html .
Groups and forums that may help you and of course you can contact me
Leica III FB group, LTM lenses, MF lenses, MF lenses forum,
Leica III FB group, LTM lenses, MF lenses, MF lenses forum,
