FED 2 rangefinder alignment woes

[stratcat]

I have a very strange problem with the alignment of the rangefinder in my old FED 2.

I set the alignment at infinity, using the FED 50mm f/3.5 collapsible lens and the full moon as target, no problem.

But when I check the alignment the following night it's off again! Locking the lens at infinity leaves the rangefinder image just a little short of the target.

Has anyone suffered such an erratic behavior with the FED 2 rangefinder?

Also, could someone also post the orientation of the rangefinder focus cam in an aligned FED 2? I aligned mine and, though it apparently works perfectly from 1m to infinity (aside from that gets-out-of-infinity-alignment-overnight quirk) it doesn't seem to me it's orientated right. I'm attaching a picture of the cam in my FED 2.

Thanks guys!

 

[apostasiometritis]

I don't know what that thing is, but it is definitely not like the cams on any of my 2 FEDs. It should have a crescent like shape. I can post images later on.

 

[rfaspen]

Yeah, that doesn't look like mine either. Its entirely possible that thing "slips"/"rotates" with use (focusing) and carrying the camera.

 

[stratcat]

Thanks for your posts. The cam does not rotate, it's held tightly in position. The cams of old FED 2 cameras are like this (I have another old one with the same type of cam) the crescent shaped cam was introduced in later models.

 

[rfaspen]

How about the attachment of the armature? Perhaps that's loose instead? I fear that otherwise you're starting to implicate the rangefinder mechanism under the top plate. And there it could be a loose mechanical part or even a loose mirror/prism -- very hard to speculate just what it could be. Luckily, Feds are really pretty easy to disassemble, troubleshoot, and reassemble successfully. Some people even enjoy that.

 

[geoffox23]

On my three bodies, the tip of the cam points towards the right side bottom corner of the D in FED.

 

[Kumpunen]

On my three bodies, the tip of the cam points towards the right side bottom corner of the D in FED.

Same here. It's the tip that meets the lens on that model. Looks like you need to adjust yours 90° CCV.

 

[Dez]

Here is the position of the follower in my very old FED (3 digit serial #) It seems to focus properly.



Cheers,
Dez

 

[stratcat]

How about the attachment of the armature? Perhaps that's loose instead? I fear that otherwise you're starting to implicate the rangefinder mechanism under the top plate. And there it could be a loose mechanical part or even a loose mirror/prism -- very hard to speculate just what it could be. Luckily, Feds are really pretty easy to disassemble, troubleshoot, and reassemble successfully. Some people even enjoy that.

That's my fear, that it might be some loose lens or mirror. I have in fact disassembled the top of this one to give the parts a good cleaning. I did not notice any obviously loose parts there, thus why I wanted to ask if someone had had this weird behavior with the rangefinder.

On my three bodies, the tip of the cam points towards the right side bottom corner of the D in FED.

Same here. It's the tip that meets the lens on that model. Looks like you need to adjust yours 90° CCV.

Here is the position of the follower in my very old FED (3 digit serial #) It seems to focus properly.



Cheers,
Dez

Thanks guys. That cam tip open like that on mine did not really feel right. Have any of you checked that focus at 1 meter is correct on the rangefinder and on the film plane?


Thanks again.

Cheers!

 

[Dez]

All I can say is that pictures shot at close range are correctly focused. I have not done an explicit test. I have seen other old FEDs with a similar configuration.

Cheers,
Dez

Cheers,
Dez

 

[RichL]

One other possibility. If you are aligning outside and it is quite cold then checking it when the camera is warm there could be a drift.

 

[KnipsOmat]

The teardrop-shaped cam on my older FED-2's (and on FED-1's, which is alike) are orientated just like the one on the photo provided by Dez. The tip should be facing the rear of the lens. Yours is about 90° off the correct position.

I've once had shift problems due to temperature differences on a Zorki-4, as described by RichL - but the other way round. Aligning inside in warm, rangefinder was off outside in cold after some time, when the camera got cold. Quite a bit so.

Another source of trouble could be a rangefinder arm that is not moving freely, so it will not always follow the lens's movements, but "hang" in a position somewhat away from the lens's back. Old grease and dirt might be the problem there. Have you checked that everything is always moving freely?

On rare occasions, positions of camera rangefinder cam and rangefinder cam on lens back can be so far out of alignment, that the two don't meet correctly when you screw in the lens. I have a FED-3 and a Jupiter-12 which works on any other camera I have, but not on that particular FED-3. You can hardly screw it in and rangefinder gets blocked by the lens if you do so. Have you checked from behind with open back and open shutter, when lens is mounted, that everything is in correct position in relation to each other?

 

[Dez]

After you get the cam oriented correctly, there is some work to do to get the RF set up properly. As I imagine you know, the horizontal adjustment is under the screw below the Russian E on the front. It is entirely possible that you can't set the rangefinder to work properly at infinity with this screw alone, as some radical adjustment must have been made to compensate for the wrong position of the cam. If so, the first thing to try is to unscrew the round bezel in front of the rangefinder window, and turn the slotted collar under it which is intended for vertical alignment of the RF. There will be two positions of this ring that give correct vertical alignment, but with a major change in the horizontal alignment at these two positions. You will probably be able to get the RF aligned to infinity properly in one but not both of these positions. If this still doesn't do the job, you will need to pop the top off and undo whatever hack job was done on the RF linkage to get it to indicate properly at infinity with the cam out of position.

It is common to find that some glue has been put on the vertical adjuster ring, either at the factory or by a camera repair person somewhere along the line. This can make turning the slotted ring a bit of an adventure.

Cheers,
Dez

 

[stratcat]

Gentlemen, thank you all for your posts. They have been very helpful in today's odyssey while I tried to get the rangefinder aligned in that old FED.

At first I moved the cam back to the general orientation shown in the picture kindly posted by Dez. However, no matter how I orientated it, I wouldn't get below 1.5m as indicated in the lens.

I tried other lenses, an Industar 26 and a Canon 35mm f/2.8 with the same result. Maybe there's something wrong with my setup, I thought. So I brought out the old Kiev 4. The rangefinder image coincided precisely with the lens setting at 1m.

I had just about given up when I thought I'd actually move the camera along the flexometer until the rangefinder patch matched. Surprise, surprise, the adjustment wasn't long, but short. Without a lens screwed on, the rangefinder coincided at about 60 cm. With a lens screwed on and the cam adjusted so that it would be the most sensitive, the rangefinder coincided at 80 cm!

How was this possible? There was no way I could turn the sensor cam that it would increase the distance, so was this camera defective? maybe that's why they switched to the other crescent shaped sensor cam? Once again I gave up and started gathering all the tools when a crazy idea popped into my head. What if that screw under the 'E' also affects the 1m setting? It's supposed to only be a stop at infinity but what if...?

With nothing to loose I fetched the camera again, setup the flexometer on the table, the target at 1m, unscrewed the covering screw under the E, inserted a jeweler's screwdriver until it caught the adjustment screw, looked through the viewfinder and turned the screwdriver and... it turns out it does move the adjustment at 1 m. Even with no lens screwed on, turning that screw moves the rangefinder image.

As far as I knew this was not supposed to be, that screw only sets the stopping point of the mechanism at infinity. Yet if you look through your viewfinder, with no lens on or a lens set at the minimum focus distance, the rangefinder image will move. At least it does in this old FED 2 with no flash sync.

So now, I thought, I'll set up the rangefinder precisely at 1m with the lenses but... what about infinity?? Well, after setting the rangefinder image and the lens to coincide at 1m, I went outside and focused on the hills far away, expecting the adjustment to be far off. Well, what can I say, it matched. Perfectly.

Now I don't want to say you should go and test and/or fiddle with the adjustment in your own FEDs... but on the other hand it would be nice if someone checked and see if the infinity adjustment screw in your own FED also moves the rangefinder image when it's not set at infinity 🙂 .

Long story short I got my rangefinder aligned, annoyed my wife, 'wasted' a whole day on this and discovered things are not that simple as they're supposed to be.

Now the real test will be tomorrow. Will my adjustment stay put? I'm keeping my fingers crossed.

 

[Dez]

It isn't an "infinity adjustment screw". It adjusts the Rf linkage, whether there is a lens on or not. Usually the RF is set at infinity, as it is easy to find distant targets. You set it first at close range, and it looks like you got it right. By slightly changing the angle of the cam, you can correct for both infinity and close range, but this is a fiddly iterative process.

Cheers,
Dez

 

[stratcat]

It isn't an "infinity adjustment screw". It adjusts the Rf linkage, whether there is a lens on or not. Usually the RF is set at infinity, as it is easy to find distant targets. You set it first at close range, and it looks like you got it right. By slightly changing the angle of the cam, you can correct for both infinity and close range, but this is a fiddly iterative process.

Cheers,
Dez

It most definitely is a fiddly and iterative process!

Thank you Dez! I was under the impression that the screw was only a 'stopper' of the linkage as it approached the extreme where the lens was focused at inifinity. And that the cam was the adjustment at the other extreme, when the lens was at its closest focus setting. Clearly I was wrong and, as you mention, the screw adjusts the RF linkage. Live and learn!

I learned a whole lot more today, thanks to everyone's posts and the actual experimentation, about how this cameras actually work.

Now I think I'll have a go at repairing the loose ribbon of the second shutter curtain in my other FED 2...

Thanks again!

 

[mburns]

Use the cam to fix close focus on Leica lenses.

Use the cam to fix close focus on Leica lenses.

So anyone could slightly shorten the lever arm of this cam in order to bring standard Leica lenses into correct calibration up close.

It is interesting also that my late production FED-2 (with no strap lugs and a nylon covering) arrived from Synoptics Camera adjusted with a sharp tip on the cam fully extended at maximum length on the lever arm. But I had not detected a problem with focus close in.

Hmm, the rangefinder has this camera front focusing by 2 or 3 cm close in. So I would need to to shorten the effective lever arm by .4 mm or so to remedy this.

 

[Dez]

Moving the cam has the effect of lengthening or shortening the arm, as well as changing the horizontal alignment at infinity. That's how the RF could be corrected at both extremes. I don't see any reason why that adjustment couldn't also be used to handle a slightly different focal length, but I have never tried it.

Cheers,
Dez

 

[wolves3012]

With regard to the OP, that cam does look wrong. However, the purpose of the cam being movable is to allow correct adjustment, in combination with the "infinity screw", of the rangefinder. The exact position the cam ends up in isn't at all meaningful (if it looks somewhere sensible) and no two cameras would be expected to be the same.

 

[mburns]

I now think that I am looking at a variable arm length design here - implemented by the curved surface of the cam. The purpose, I think, is to reduce back focus at a distance of 3 meters while also being accurate at 1 meter.

My FED-2 still has about .4 meters of back focus at a distance of 4.5 meters, but it has no back focus at 3 meters.