FEDs and Leica thread mounts

[PeterW]

Gene and Wayne: I have a small oops! apology to both of you.

Gene, when I mentioned the thumb-aching rewind I was thinking more about the FED 4 than the FED 5. On the FED 4 the rewind is a thumb wheel sticking out the side of the camera. I think they put it there because they put the meter knob on the top plate. Whatever the reason it's a pain to use, and on the FED 5 they did away with it.

Wayne (and Gene), I should have remembered that all FED 2 cameras are post-war. I THINK I'm right in saying that on early (many pre-war) FEDs the lenses were matched to the camera with regard to lens back focus and flange to focal plane distance as, indeed were the very early Leicas, so although they unscrew you shouldn't just swap them around willy-nilly.

Put it down to tiredness late at night (at least, that's my excuse!).

Related to all this, in a way, is the Leica thread mount itself which is 39mm 26 threads per inch, Whitworth thread form. Why should a German company use a mixture of metric and English Imperial standards?

I read somwhere that this was to confuse competitors, but I think that's fanciful. I prefer the version which says that in the mid 1800s, long before the Leica was even thought of, Leitz was making microscopes and microscope lenses. I believe they were the first company to produce a turret microscope lens cluster. At that time England was acknowledged as the leading country for high quality microscopes which were sold all over the world. So, to make its lenses compatible with English microscopes, Leitz equipped its machine tools with cutters for Whitworth form threads with the pitch in inches instead of millimetres. This practice hung on right through to the Leica thread mount.

When the Russians first copied the Leica in the 1930s, either they mis-read their thread gauges or decided that because their machine tools were all metric they weren't going to mess about with inches and an English thread form. So they made the lens mount 39mm diameter by 1mm thread pitch (26 tpi is about 0.976mm pitch). They also used a metric thread form which has a slightly different flank angle from the Whitworth thread form.

I'm told, though I haven't any evidence to support this, that after the war the Russians changed to 26 TPI Whitworth thread form because camera makers in other countries who made Lieica clones or near copies used the same thread. At any rate, my Industar and Jupiter 39mm lenses fit snugly and smoothly into both my pre-war Leica cameras, and my pre-war Elmar and Summar fit nicely into my FEDs and Zorkis.

But, I'm told, early Russian 39mm screw thread lenses will bind and go tight in a camera with a true Leica thread mount, and vice-versa. I can't vouch for this because I haven't got any early Russian 39mm lenses, nor an early pre-war FED body.

Nice story, even if I haven't got it absolutely correct. Anyone like to confirm it or correct it?

BTW, if anyone needs to strip an Industar to relube the helicoid Matt Denton has all the details with pictures on his website
mattdentonphoto.com/cameras/industar_relubing/index.html together with a lot of other interesting stuff.
If you don't know it it's well worth a visit and browse around.

PeterW

[doubs43]

Peter, your explaination of Leitz adopting the Whitworth thread pitch so that their microscopes would be compatable makes perfect sense. When a rival has the lion's share of the market and you wish to compete, making your products work with theirs is simply good business.

Many people don't realize that the Japanese were turning out first class optical equipment prior to WW2; world class quality optics that gave their post-war camera and lens makers valuable experience to build upon. In the US, following the war it was thought from the products imported that they only made cheap toys. I well remember the tin crickets and such being sold in the late '40's and early '50s.

While early post-war cameras often had mounts that were not compatable with foreign makes, it didn't take the Japanese long to adopt the M39 Leica, Contax bayonet and M42 Praktica mounts as they began their assention to the top of the camera world. Later, of course, they began using propriatary mounts as people accepted their products as being more than mere copies of German cameras and lenses. The Korean War and David Douglas Duncan's images shot with Nikkor lenses opened the eyes of the world to Japanese quality. The rest is history.

Addressing the Russians is another matter altogether. They "copied" German cameras but not exactly and often added their own twists, usually with the goal of simplifying manufacture. Examples include changing the roller bearing rangefinder cam in their Leica clones to a tear-drop shaped cam which can be a nightmare to work with. (DO NOT try to use the 135mm Leitz screw-mount lenses on a Russian camera with the tear-drop cam. They are NOT compatible! Nor are the shorter lenses that have a gap in the lens RF cam. While the Leica roller will pass over the gap, the tear-drop will hang up on it. Sometimes the tear-drop doesn't engage the RF cam of the lens at all because it's not at the proper level.)

It's also a fact that the flange-to-film plane distance is not the same on FSU cameras as it is on the Leica. Thus you may find it necessary to re-set the infinity focus on Russian lenses if used on Leicas or their Japanese clones. (Leica is set at 28.8mm but I'd have to look up the Russian standard.) I have read that the Russians made it clear to consumers that in most cases they would get the best results if a lens was adjusted for a specific camera body. My experience with FSU cameras would suggest that it's true.

Quality control seems to have been a foreign concept to FSU factories that were directed to produce quantities that made close attention to detail impossible. I own a Moskva-4 folder that is a close copy of the Zeiss-Ikon Super Ikonta C. My first exposures through this pristine , like-new, camera were all slightly out of focus. I used a ground glass and 10x loupe to set infinity focus to critical sharpness and my second roll was tack-sharp. It may also explain why the camera is so nice cosmetically. The previous owner wasn't satisfied with the pictures it took so they put it away where it remained until I bought it. A trip to a repairman would have corrected the problem and they would have had a quality camera. The factory couldn't be bothered with setting critical focus.

FSU optics can be brilliant or miserable..... again, the result of poor or non-existent quality control. It's reported that some years are much better than others. Mechanically the lenses are often not anywhere near German or Japanese standards and the yak snot they used as helical lubricant will harden over time, making a re-lube almost a certainty. Newer lenses may be better in that regard but the old FSU lenses will almost always suffer from poor lube.

A complete study of FSU cameras and lenses would take a lifetime. Princelle's books on FSU equipment is worth a look if anyone is interested and, for repairs, Maizenberg's book is almost essential.

Walker

[kiev4a]

Walker:

The post war FSU 39mm mount lenses were 28.8 backfocus--at least they were supposed to be--but quality control sometimes wasn't up to snuff. FED and Zorki both used that measurement on virtually all their models. It is my understanding that after the war some of the first FEDs had the old thread pitch and backfocus distance (prewar parts being used up). The FED plant was pretty much destroyed in the war so KMZ built a FED/Zorki Leica II clone for a short time until the FED factory got back on line.

You can also run across an occasional pre-war FED that has had the mount and lens changed to post war standards at some point by someone.

There also are a lot of "part is parts" cameras floating. Nearly all parts on FED and Zorki Is plus a lot of pieces from the Zorki 2S are interchangable and Ebay sellers sometimes pulled parts from one brand or model to fix another brand. I have one camera--allegedly a Zorki 1 that has a late Zorki 1 top and an early top plate which means there is no serial number--plus a FED I shutter crate and shutter speed gear train from a Zorki 2C!!

Hardened grease is the Achilles Heel of most FSU cameras and lenses. It is surprising how smooth some of these cameras can be after a CLA. The most notorious lens for grease problems is the 85mm f2. Any lens in original condition has hardened grease and when amateurs try to relube them they almost always get the lens back together wrong.

The smoothest Zorki I have is a Z1C that I completely stripped and polished all the shutter train contact points (no bearings). Then a guy in the Philippines sent me some extra thin shutter curtain material he made himself. The shutter goes "snick" instead of "clack" And so far the curtain material has held up well.

I have a couple of prewar FEDs and their lenses bind up in a postwar mount although it probably would be possible to screw them in with enough force. Then there would be a problem with getting them unscrewed.

[doubs43]

Wayne, the key IMO is "supposed to be". I think that military procured cameras were far better quality-wise, but consumer products suffered from being rushed to meet Central Planning Commission goals. The system was it's own worst enemy.

I have a fair collection of FSU cameras and lenses that I purchased between 2 & 3 years back when they were plentiful and cheap. Swapping lenses between cameras - especially the Kievs - has given mixed results.

When I get home tonight I'll check my copy of Maizenberg's book and see what he says about back focus. While I agree that it was standardized after the war, I'm not certain it was set at 28.8mm as the Leica is. I could be wrong (and am too often) but I seem to recall a different standard. I'll let you know what I find later.

I've read reports that CLA'd and calibrated FSU cameras are remarkably smooth. All of mine are pretty much as they came from the factory.

Walker

[PeterW]

Hi Wayne,

Was the guy in the Philippines who sent you the shutter material Jay Javier? I’ve never corresponded with him, except a couple times on a couple of forums, but from his writings he’s very knowledgeable abut FEDs, Zorkis and other FSU cameras. For anyone interested in FSU cameras, and in particular with the subject in this thread, have a look at this page on Jay’s website www.jay.fedka.com/index_files/Page422.htm about lens flange to focal plane distance, and about setting up the rangefinder accurately.

In particular read carefully what he has to say about the press-fit of the curved rangefinder cam on its arm, how this can be knocked out of kilter by screwing in a lens that isn’t set at its closest focusing distance, and how to adjust it to get the rangefinder reading correctly at close distance. I picked up a Zorki 4 a few years ago where this cam had been knocked wonky, and I fiddled and scratched my head for ages trying to find out why the rangefinder was out at close distances – until someone pointed me at Jay’s website. Then I got it spot on first time. The rest of his website is also well worth perusing.

As you say, the lens flange to focal plane distance is 28.8mm (NOT 27.8 as I’ve seen on another otherwise excellent website). The tolerance is the same as the Leitz tolerance, plus or minus 0.02mm. In other words, 28.78mm to 28.82mm. So far, all my FSU cameras have been OK in this respect, but then all but two were imported into the UK by the old T&OE company in London who checked things like this on every camera before it went out to dealer.

How can you check whether this is OK without special equipment, especially on bottom loading models where you can’t use a piece of ground glass in the film plane? In one of my notebooks I’ve got a sketch of a VERY simple little ‘special tool’ you can make to use with a cheap (but usually accurate) Chinese or Korean digital readout calliper. You can use it for checking the distance and that the flange is parallel to the focal plane.

My notebooks are far from organised or indexed, so it will take me a little while to find it, but in the next day or so I’ll scan it in and post it together with notes on how to use it. It’s not one of my brainstorms, I got the idea from another camera tinkerer in the UK. I tried the one he made on one of his cameras, and you can’t go wrong. I’ve been promising to make myself one for ages, but it’s one of those jobs for which I’ve got to get a Round Tuit. One day, when I really need it, I will.

If you want to go deeper inside a FED, like renewing shutter curtains, have a look at this page on Stephen Castello's website stephenc7.tripod.com/cameras/fed2.htm
Going inside a Zorki is almost identical, and the later FEDs and Zorkis with removable backs aren't all that different inside.

PeterW

[doubs43]

Wayne & Peter, Maizenberg confirms that the back focus standard established for FSU cameras using Leica screw mount lenses was 28.8 + or - 0.02mm..... exactly as you both state.

Walker

[kiev4a]

Peter.

Yes, Jay Javier was sort of my mentor on FSU camera repair issues. He walked me through my first curtain replacement by email. It took three weeks (mainly because the old curtains had detached so I didn't have a reference point) Jay's curtain material seems to be holding up fine. He's not active in the FSU community now and I usually try to get hold of him every year or so to say hi. Jay's site is more useful as far as I'm concerned, than Maizenberg's book--at least for Leica II copies. I had an English copy of Maizenberg's book for awhile but eventually sold it because info was available on line..

This is what I use for backfocus checking, Just a piece of aluminum stock with a brass rod exactly 28.8mm long (the tip polished so it won't scratch. The aluminum bar rests in the lens mount. You should make such measurements with film across the pressure plate. When the tip just touches the film you have the proper distance.

[PeterW]

Here's the sketch from my notebook of my friend's backfocus checking tool to use with a digital caliper. The dimensions aren't critical.


It's exactly the same idea as yours, Wayne, but I prefer this as it's easier to make, and not limited to one depth. It can also be used on M42 cameras, and bayonet mounts where you don't have to measure from an inner lip.

I agree with you about putting a piece of scrap film in the camera to measure to. That, after all, is where the lens should focus, and it also saves any scratching of the pressure plate by the probe.

This is my digital readout caliper. Not expensive but accurate. I've had it about two years and, with care, it should last for years more. It's still running on the original SR44 silver oxide battery. I've still got my expensive vernier caliper that I've had about thirty years as a back-up if needed, but with my old eyes I was finding it difficult to read the vernier divisions accurately without a magnifying glass. The digital one is so much easier.


Come to think of it, I haven't seen Jay Javier on the forums for quite a time. Other people who have helped me a lot are Rick Oleson, still very active on various camera repair forums, and with Prakticas Bob, handle Toolmaker 44, on the Yahoo Practica Users Group.

I used to be quite active on a number forums, but not so much now - too busy on this one!!

PeterW

[doubs43]

Peter & Wayne, those are both useful jigs that allow checking back focus at all points in the film gate. I do like Peter's setup for it's ability to be used on more than just Leica and Leica clone bodies.

At the moment my calipers are of the dial type so I can see a digital caliper in my future.

Thanks to both of you for a couple of great ideas.

Walker