Zorki's and Feds, Different Lens Specs?

[CameraQuest]

A couple of years ago a friend told me that it was well known and accepted in Eastern Europe that Zorki's and Fed screw mount lenses were actually made to different lens specs.

Supposedly one was produced to the Leica lens standard focal length normal, while the other to the Kiev-Contax standard focal length normal. (Sorry, forgot which was supposedly which)

Can anyone substantiate, explain, or completely refute this theory?

Stephen

 

[Murray Kelly]

Stephen, AFAIK the 'powers that be' in the old Russia decided that, since they had no particular commercial imperative to conform to the original Zeiss/Leica standards in the cameras they made, and since also they had the entire Ziess factory rebuilt in Kiev it made sense to standardise on the Ziess 52+mm Kiev standard focal length. Only the mount would vary.

This meant that the FSU LTM lenses would focus on infinity on a 'real' Leica but the extra mm or so in the focal length would mean that a rangefinder adjusted for the 51mm Leitz lens would not quite indicate true at, say, 1 meter. Only a few inches but enough to give some folk angst. It is claimed that it can be adjusted out by reshimming the lens barrel but I can't quite see how a 52mm lens can be made to be the same as a 51mm lens. The alternative is to adjust the rangefinder itself or get used to it! Allow for the fact that you focus on the ears and not the eyes for portraits.

I'm sure you will get better and more detailed replies from others.

Murray
Brisbane, Oz

PS the Bessa R continues to work well especially w the Snapshot w/a.

 

[darkkavenger]

Maybe this would refer to prewar lenses and bodies, made before the introduction of Zeiss designs known as Jupiter lenses (from what I've read somewhere, the russian pronounciation of Zeiss is similar to the greek god Zeus -> hence the roman god Jupiter name) ... the 1930's Leica mount bodies were engineered by copying the Leica cameras, but after the introduction of the Jupiter lenses, which were primarily designed for the Contax system.. I don't think that the russians bothered changing everything. Maybe they added some shims for f/2 and f/1.5 lenses only.

although some Zeiss lenses were made in LTM during wartime, especially the Biogon and Sonnar... maybe the russians also acquired the plans of these zeiss designs in LTM.

it would be interesting to compare in this view Pre-1945 "Fed" & "Industar" lenses with their postwar companions, and how the lenses have evolved (from the I-22/I-50 to I26m & I61)



this is just a theory. I am by no means expert or acknowledged in things that contain measurement units below the centimeter graduation. 😀

just throwing a message in a bottle! 😉
and time to go to bed, this seems really too unstructured, the stuff i'm saying!

cheers,
max

 

[payasam]

You may be right, Max, but it is my understanding that FSU names are based on astronomy: Jupiter, Helios, Orion...

 

[wolves3012]

Zorki and FED lenses were made to a fractionally different standard from Leica's. If I understand it correctly, the difference relates to the lens focal length and the throw of the helicoid. On a FED or Zorki, it's possible to adjust the RF at both ends of the scale - near and infinity - this is not possible on a Leica without re-engineering the RF mechanism, hardly practical.

The net result is that an FSU lens doesn't focus accurately on a true Leica-standard body, at the near end. I've tried a Jupiter 8, Jupiter 12 and an Industar 22 on my Leica IIIC. The J-8 was slightly off at near focus, as expected. The J-12 was fine, probably due to greater depth-of-field inherent in a wide-angle. The I-22 was near enough for all but the most critical close-focus.

To some extent there is an element of pot-luck, some people find an FSU lens to be ok as it is. It is possible to make adjustments to some lenses to correct them, Brian Sweeney or Kim Coxon seem to be the acknowldged experts on this.

 

[wolves3012]

It is claimed that it can be adjusted out by reshimming the lens barrel but I can't quite see how a 52mm lens can be made to be the same as a 51mm lens..

On some lenses it's possible to adjust the element spacing, hence changing the focal length slightly. I'm not sure of the exact figures, but the difference isn't as great as 52 to 51mm, it's something more like 52.6 to 52.4mm. I believe that lenses often focus to just beyond infinity anyway, in which case re-shimming the whole block can be enough in some cases.

 

[Murray Kelly]

Thanks Brian, you have re-engineered the lens. I dunno how you got the .4mm but I bow to your greater experience here. The shot you show seems to lack a certain 'snap' but posting is as I find, a bit of a crap shoot. Lots of detail lost.

With incredible respect, one is fiddling (for want of a better word) with a precision instrument when the groupings are changed internally.

The bottom line for me is, I suppose, accept the 5cm difference at portrait distance and adapt my stance accordingly. Lean back 2" after focussing on th eyes. A calibrated lean? 🙂

I have just been thru the process of cold bluing the blades of the Helios and screwed it up by getting the blue solution on the lenses. :-( It etches the glass! I have another and, hey, they're cheap but good.

But back to the theme, how can we mere mortals adjust something like a beautiful thing like a Helios so finely? Not easily I suggest. I have the gear (micrometers etc) but it takes a lot of hands on experience to get it right. Unless one does this thing often it's bound to go wrong more often than not.

In a nut shell, what I'm saying is, it ain't as easy as you suggest!

Murray
Brisbane, Oz

 

[brachal]

Looking back to the original question ...

I've never heard that Fed and Zorki lenses were produced to a different spec from each other. Different from Leica, sure, but not each other. Post-war, technicians from Fed actually provided (with some help from captured German engineers) the technical expertise that allowed the introduction of the Zorki. Having said that, I can't rule out that the lenses were produced to different specifications.

A couple of points that could be read either way ...

There are stories on the web that the various Feds were not really intended to be interchangeable lens cameras. There's no mention of changing the lens in the Fed-2 manual I've seen -- a curious omission. Very early Feds, like early Leicas, were individually matched to their lens.

Fed lenses (FED 50mm f/3.5, I-26, I-61) only seem to have been produced by the Fed factory, while the various Zorki lenses (mostly Jupiters) were produced at KMZ and several other plants.

I don't think we can say for sure either way unless somebody with a large sample of lenses decides to do a test. Completely unscientific, but I've used Fed and Jupiter lenses on my Leica and Bessa R without noticing one focusing better than the other. Of course such a shift should only be noticeable at very close range and widest apertures.

 

[wolves3012]

Looking back to the original question ...

I've never heard that Fed and Zorki lenses were produced to a different spec from each other. Different from Leica, sure, but not each other. Post-war, technicians from Fed actually provided (with some help from captured German engineers) the technical expertise that allowed the introduction of the Zorki. Having said that, I can't rule out that the lenses were produced to different specifications.

A couple of points that could be read either way ...

There are stories on the web that the various Feds were not really intended to be interchangeable lens cameras. There's no mention of changing the lens in the Fed-2 manual I've seen -- a curious omission. Very early Feds, like early Leicas, were individually matched to their lens.

Fed lenses (FED 50mm f/3.5, I-26, I-61) only seem to have been produced by the Fed factory, while the various Zorki lenses (mostly Jupiters) were produced at KMZ and several other plants.

I don't think we can say for sure either way unless somebody with a large sample of lenses decides to do a test. Completely unscientific, but I've used Fed and Jupiter lenses on my Leica and Bessa R without noticing one focusing better than the other. Of course such a shift should only be noticeable at very close range and widest apertures.

I don't think the OP meant that FED and Zorki lenses were different from each other, merely that the FED/Zorki lenses were not made to Leica standard. This seems to be true from my and other people's experience and from the information available.

Regarding FED and Zorkis, it's certainly correct that early bodies were adjusted for the original lens, based on measurements people have made of the lens-to-film distances. In that sense they weren't really interchangeable-lens cameras, merely replaceable-lens cameras. For later models they do appear to have standardised though, that would include the FED 2.

 

[brachal]

Supposedly one was produced to the Leica lens standard focal length normal, while the other to the Kiev-Contax standard focal length normal. (Sorry, forgot which was supposedly which)

The quote above makes me think Stephen's question is, in fact, whether Fed and Zorki lenses are different from each other. Maybe he will notice and clarify.