What would these lenses be used for?

I have two lenses, both with 39 mm thread mounts. One is a Russian Industar 50 mm f 3.5 with a focus scale down to 0.65 m. The other is a Carl Zeiss Tessar 50 mm f 2.8 Nr 1616705. I have tried both these lenses on my Leica II and was very surprised that neither focussed properly, although screwed in easily both were in the wrong position to focus correctly. I have tried them both on my Zenit E, holding each one on the flange of the mount (as if they were mounted with an adapter) however neither focussed properly on the SLR. Neither looks like an enlarger lens so I am puzzled. I would be grateful for any comments and advice

Do you have any photos? The Industar-50 was available in 39mm thread mount for the Zorki and FED rangefinders, as well as M39 for the early Zenit SLRs (the Zenit 3M, Kristall and some of the early Zenit-E models). The threading is the same, and they look similar, but the rangefinder version has three knurled rings (excluding the aperture ring) while the SLR version has two knurled rings, is a bit shorter, and of course lacks rangefinder coupling. Also, If the minimum focusing distance is 0.65m, then it sounds like the SLR version. The RF version would only focus to 1m.

 

The M39 SLR version should give correct infinity focus on a M42 screw-mount SLR using a M39-M42 adapter. If it doesn't, then perhaps it has been tampered with or modified by a previous owner to give infinity focus on a different camera system.

Edited April 28, 2021 by m42dave

As indicted, the Soviet M39 thread cameras were made for the Soviet RFs and for the SLR 39mm mount.

 

Things for 39mm diameter mounts were more varied (M39x0.75, M39x1.0, etc.) than the M42 or M52 mounts introduced later on.

 

If it would focus, I'd strip of the rest of the finish on the lens to match the camera! The people at Leitz would probably spin in their graves.:eek:

They might be enlarger lenses.

 

I had some weird Soviet-era lenses in M39 that I could only use with extension tubes/bellows.

 

The Chaika used M39 mounted lenses as well, but the registration distance is off by at least a millimeter

Right, the 50mm Industar was the budget choice for people buying a Zenit B or E, with the Helios 58mm f2, being the "expensive" variant. I would not expect the enlarger lens to have any focusing ability. I did have a Russian enlarger, that may well have had a 50mm f3,5 enlarging lens, back in the 70s, not sure if was called Industar though. Edited April 29, 2021 by Robin Smith

Sorry for the poor quality (and the dust!), but here is a quick comparison of the SLR mount Industar 50 (-2) and the Chaika with Industar 69 (28mm/f2.8):

 

 

I don't have a LTM (rangefinder) Industar, but it's about 16mm (2/3 of a film can diameter) longer to account for the difference in flange-film distance.

 

M39/M42 Industar minimum focus is 0.65m, so I think that's what you have...

Many thanks for all that information. My Industar is just like the SLR version shown. I presume the Tessar is for an SLR of some sort. I'll do some photgraphs tomorrow - can't find the ones I took the other week!

I presume the Tessar is for an SLR of some sort

I'm not aware of any CZ Tessars in M39 made for SLRs. It could be from one of the Braun Paxette rangefinders, which also used a 39mm thread mount but a different register distance from Leica.

There is a Tessar in M40 thread - to fit the Praktiflex - but you wouldn't screw that into an M39.

One is a Russian Industar 50 mm f 3.5 with a focus scale down to 0.65 m.

 

I actually missed this bit the first time, this does actually describe the SLR version of the I-50. They DO focus down to 0.65m, instead of 1m on the LTM version.

I'm not aware of any CZ Tessars in M39 made for SLRs.

Me neither.

I seem to recall that there was an early Contax or VEB Pentacon SLR that used a 39mm screw thread. But I could easily be mis-remembering that.

Here are some pictures (hopefully - as this is a little new to me):

Thanks

Here are some pictures (hopefully - as this is a little new to me):

Thanks

Nope, no pictures.

 

Use the 'upload a file' button, then choose 'insert image'

Let me add to the confusion. I remember reading that when the first Zorkis SLRs were made they had their own lenses as the the others M39 Leicas for some reason could not be used. I don't remember how the story ended as this morphed into the Zenit as some stage IIRC. The theory of the Paxette is good for the Zeiss,. So many 2.8 Tessars out there in various mounts. Taht it is 2.8 seems of later vintage has most pre-war are max 3.5... is /are either lenses coated?

Let me add to the confusion. I remember reading that when the first Zorkis SLRs were made they had their own lenses as the the others M39 Leicas for some reason could not be used. I don't remember how the story ended as this morphed into the Zenit as some stage IIRC. The theory of the Paxette is good for the Zeiss,. So many 2.8 Tessars out there in various mounts. Taht it is 2.8 seems of later vintage has most pre-war are max 3.5... is /are either lenses coated?

I'm confused Chuck... not quite sure what you're trying to say?

 

The Zorki was a rangefinder.

The 'Zorki SLR' was always the Zenit.

The Zenit used the M39 (M39x1) lens mount with a flange - focal distance of 45.2mm

Rangefinders use the LTM (39mm x 26 tpi) mount with a flange - focal distance of 28.8mm

(Zorki and FED may actually use M39x1 - the two are close enough that they will mate, but they still have a 28.8mm FFD)

 

Here is a Zenit (1) from 1955, sporting, coincidentally, an Industar (20 I think, not the later I-50):

 

This article below shows a Braun Super Paxette II BL with a Tessar mounted:

 

The School Teacher’s Leica – Braun Super Paxette II BL – zeitmaschinen.org

Edited May 1, 2021 by m42dave

The early Praktiflex (the Practica precursor) did have a narrower thread mount than 42mm.my early Victar measures 39,7mm: close enough to 40mm

 

p.

I'm confused Chuck... not quite sure what you're trying to say?

 

The Zorki was a rangefinder.

The 'Zorki SLR' was always the Zenit.

The Zenit used the M39 (M39x1) lens mount with a flange - focal distance of 45.2mm

Rangefinders use the LTM (39mm x 26 tpi) mount with a flange - focal distance of 28.8mm

(Zorki and FED may actually use M39x1 - the two are close enough that they will mate, but they still have a 28.8mm FFD)

 

Here is a Zenit (1) from 1955, sporting, coincidentally, an Industar (20 I think, not the later I-50):

 

 

I was speculating that the early Zenith ( as it evolved from the Zorki ) may have used a crossover 39 mm lens with a modified FL. I recall reading that the first Zenit had its own lenses at first. I admit I don't know. I recall reading that on a web page about the evolution of the Zenit. I may well be wrong. If the Industar 50 came later than I'm definitely on the wrong track. Sorry! This (below) may be my "confusion"

 

I found this now on Camerapedia Zenit

 

"

The original Zenit was an SLR based on the Zorki rangefinder.

 

The early Zenit SLR have a specific screw mount, 39mm in diameter, sometimes called "ZM39" (or "Zenit M39") to distinguish it from the regular M39 (or Leica thread mount). If you mount an LTM lens on these cameras you can only focus at close range, not at infinity, due to the lens position."

 

Sorry

I was speculating that the early Zenith ( as it evolved from the Zorki ) may have used a crossover 39 mm lens with a modified FL. I recall reading that the first Zenit had its own lenses at first. I admit I don't know. I recall reading that on a web page about the evolution of the Zenit. I may well be wrong. If the Industar 50 came later than I'm definitely on the wrong track. Sorry! This (below) may be my "confusion"

 

I found this now on Camerapedia Zenit

 

"

The original Zenit was an SLR based on the Zorki rangefinder.

 

The early Zenit SLR have a specific screw mount, 39mm in diameter, sometimes called "ZM39" (or "Zenit M39") to distinguish it from the regular M39 (or Leica thread mount). If you mount an LTM lens on these cameras you can only focus at close range, not at infinity, due to the lens position."

 

Sorry

No need to be sorry, the internet appears to be very confused by LTM and M39!

 

Leica Thread Mount is a 39mm x 26 turns/threads per inch Whitworth thread (0.977mm pitch), with a flange - focal distance of 28.8mm.

 

Soviet rangefinders actually use a 39mm metric thread with a 1mm pitch, but still with a flange - focal distance of 28.8mm.

 

M39 (Zenit) mount is a 39mm metric thread with a 1mm pitch, with a flange - focal distance of 45.2mm.

 

As far as can be known, it would appear that when the Soviets copied the Leica to create the FED and (later) Zorki cameras, they adapted the design to the tooling they had available, hence the change from Whitworth to metric thread for the lens mount. The two are close enough that they will typically interchange, but not always (my Jupiter 8 will not fit my Canon rangefinder).

 

The Soviets simply reused the existing Zorki/FED screw mount when it came to designing the Zenit, but increased the FFD to allow room for the reflex mirror. I don't know if it is by coincidence or design, but M39 (FFD - 45.2mm) is close enough to M42 (FFD - 45.46mm) that the lenses can be used on that mount with a simple thread adapter, depth of field and general slop in the focusing mechanism typically covers the 0.26mm difference which technically means an M39 lens wont focus to infinity when used on a M42 camera.

 

The confusion starts when people refer to Leica Thread Mount as 'M39', as opposed to 'LTM', probably because of the well known M42 thread mount and their being unaware of the M39 mount. Neither M39 nor M42 are actually 'correct', as the 1mm pitch is much finer than the ISO standard provides for.

 

So, to sum up, at least the following exist:

 

Leica Thread Mount (LTM) - 39mm, 26tpi Whitworth, 28.8mm FFD - Leica rangefinders and copies (Canon, Nicca, Leotax, etc)

 

'Soviet Thread Mount' - 39mm, 1mm pitch metric, 28.8mm FFD - FED and Zorki rangefinders.

 

M39 (SLR) - 39mm, 1mm pitch metric, 45.2mm FFD - Zenit SLR (they later switched to M42).

 

M42 - 42mm, 1mm pitch metric, 45.46mm FFD - SLRs from Zeiss, Pentax and everybody else.

 

 

While the two rangefinder mounts will mostly interchange, there is, additionally, a difference in the RF calibration which means that they will only focus correctly at infinity.

 

 

There are also:

 

39mm screw mount (unspecified, but likely both Whitworth and metric) enlarger lenses, easy to identify as they have no focusing helicoid.

 

Chaika - Soviet half frame camera with a 39mm metric screw mount, but a different FFD, making it incompatible with anything else.

 

Braun Paxette - another rangefinder system using a 39mm screw mount, incompatible with anything else.

 

There are probably more, 39mm was a really popular size!

 

 

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As to lenses, the Industar (at least in it's main series) is the Soviet equivalent to the Zeiss Tessar or the Leitz Elmar, a four element lens of moderate aperture, f3.5, later f2.8. It was the standard or budget option on both SLR and rangefinder cameras, just as the Tessar was. There has probably been a Tessar type lens made in every single lens mount up until the 1980s or so. The Tessar formula is short enough that it will clear the mirror in an SLR, so it was quick and cheap to adapt to the new mounts, unlike the Sonnar, which essentially died out with the rangefinders in the 1960s.

 

 

--------------

 

 

Hope all that makes sense and is clearer than most of what is on the internet, if anyone spots any errors, please correct them!

I'm confused Chuck... not quite sure what you're trying to say?

 

The Zorki was a rangefinder.

The 'Zorki SLR' was always the Zenit.

The Zenit used the M39 (M39x1) lens mount with a flange - focal distance of 45.2mm

Rangefinders use the LTM (39mm x 26 tpi) mount with a flange - focal distance of 28.8mm

(Zorki and FED may actually use M39x1 - the two are close enough that they will mate, but they still have a 28.8mm FFD)

 

Here is a Zenit (1) from 1955, sporting, coincidentally, an Industar (20 I think, not the later I-50):

 

 

I guess I am too. Sorry for making more confusion. I was just speculating on the origin of the OP lens. I seem to remember reading that as the Zorki morphed into the Zenit. the early, or earliest model kept the TM39 mm. but it wasn't the same FL because of the changes needed to make the mirror box I think, So they had their own lenses. But if the Industar 50 is that much later, then again; I don't know. Just speculating.

 

I believe it was this: Zenit

 

"The early Zenit SLR have a specific screw mount, 39mm in diameter, sometimes called "ZM39" (or "Zenit M39") to distinguish it from the regular M39 (or Leica thread mount). If you mount an LTM lens on these cameras you can only focus at close range, not at infinity, due to the lens position."

Sorry, didn't make that clear above.

 

Basic optics

 

For a simple, single element lens, the focal length of the lens is the distance from the middle of the lens element (nodal point) to the focal plane, so 50mm for a 50mm lens, at infinity. To focus closer, you increase that distance.

 

So, the lens barrel for a 50mm lens will be the focal length minus the flange - focal distance (distance from the lens mount to the film), so 4.8mm for a SLR (50-45.2) and 21.2mm for a rangefinder (50-28.8).

 

So if you mount a rangefinder lens on an SLR, you are effectively adding a 16.4mm (45.2-28.8) extension tube and will only be able to focus at very close distances. If you mount a SLR lens on a rangefinder, you will be beyond infinity, the focal point will be 16.4mm behind the film plane and it won't work, not to mention the lack of RF coupling.

 

This pretty much holds true for a Tessar type lens.

 

It all gets a bit more complex with telephoto (nodal point is in front of the physical lens) and retrofocus (nodal point behind the physical lens, closer to the film).

 

This is why wide angle lenses for SLRs are retrofocus designs, the mirror prevents the lens being physically close enough to the film for, say, a 28mm focal length.

 

 

Again, if I've made a mistake or over simplified, please correct me.

 

 

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LTM being referred to as M39 irks me somewhat, not only is it the source of all this confusion, but it's simply wrong. The 'M' in M39, M42, M8 specifies a metric (ISO 68-1) thread, but LTM is a Whitworth thread...

Thanks for the extensive clarification Steve

LTM being referred to as M39 irks me somewhat, not only is it the source of all this confusion, but it's simply wrong. The 'M' in M39, M42, M8 specifies a metric (ISO 68-1) thread, but LTM is a Whitworth thread...

It gets worse when you throw enlarger lenses into the mix, that nearly all use a 39mm thread where physically possible. I'm not sure they were ever 'standardised' to a 1mm or 26TPI thread, but I still have a couple of enlarging lenses that bind slightly when offered up to a 39mm enlarger or bellows flange.

 

The ~ 30 micron pitch difference should make absolutely no practical difference to the fit of a thread over six to ten turns. So I can only put it down to a thread profile difference.... or just plain poor machining.

 

Also - geek fact - the definition of the imperial inch was only standardised to exactly 25.4mm in 1930. Which is well after Barnack and Leitz settled on their weirdly hybrid 39mm O.D. & 26TPI lens thread. Before that the UK imperial inch was about 23 nanometres shorter. Insignificant in practical terms, since most materials will shrink or grow by more than that with only a small temperature change.

Edited May 5, 2021 by rodeo_joe|1

Thanks for informative discussion. I wonder if the Tessar was made for the Paxette? Photos above.

Alan.

Apologies for duplicating pictures.