Moskva 5 lens alignment.

fidget

fidget

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A while ago I posted about a problem I have with my Moskva 5. The lens assembly is not parallel to the film plane and is easily seen to be off.

I took the lens off that and was relieved to find that it was (I thought) caused by a packing shim/washer being missing and allowing the peg at the back of the lens (the one which is at the back of the lens, which engages in a hole in the mount plate, stopping the assembly from rotating) which was "grounding" in the hole, holding the assembly away from the plate....so not parallel to the film plane. I was particularly relieved to find that the mount plate itself is parallel, so it's all a matter of shimming it out correctly.

I had an opportunity (GAS) to acquire another Moskva 5, so thought that i could use one whilst I figured a way of correcting the first (which also needs a shutter service). This one also has a none parallel lens/film plane, although in this one, it's the mounting plate which is out (makes me wonder if some were made with these problems). Doubts now set in as to whether I am seeing things. Here is how I determined what's out....

I took off the back and placed the camera on a nice straight alloy extrusion which fits inside the film gate and rests on the film rollers at each side.

I placed a 300mm steel rule edge on to the lens bezel and positioned it along the bed (the extrusion).

I measured from the lower edge of the rule to the bed in a few places. This gave me, for the last camera, a run-out of 5.05mm along the length of the rule. This translates to about 0.5mm across the lens on it's mount. Rotating the bezel had a minimal effect, so I am confident that it's not simply the bezel which is crooked.
This has got to be a very significant error hasn't it? It's easy to see that it ain't square by eye.

Although I could use the camera and try to determine if it is a problem, I much prefer to get it right before committing to real trials with film.

Anyone done this?
 
I've just measured the lens assembly bezel position at infinity and when it has moved by 0.5mm, at which point it is focussed very near to 5m, so the difference must be very significant.
 
I can see that the supports might determine the erected position of the lens assy, but if it locks neatly, I'd rather not bend this around.
Now with around six thicknesses of .5mm shims (Ilford MG4 RC) it sits nice and square (at least along the long side, maybe I shouldn't look for problems elswhere). What a fight. Can't help thinking that there must be a more elegant way of correcting this, packing one side whilst not counter packing the opposite side is a bit of a rough solution.
Now to check the rf alignment and scale focus accuracy, which I guess must now be off.
 
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Hey, this is like my own little blog, no other posters at all 😎
Well, to carry on, just in case there might be an interested party out there:

Seems that my inelegant lens plane alignment is not very good 🙁
I've run a couple of films through it, just hand-holding at 1/250th apart from my usual blank frames intended to catch leaks.
The leaks are there all right, even after liberal use of some foam from a kit for sealing these. More investigation required for this/these leaks. Seems also that in common with my first Moskva5, I need to address leaks around the red window, which looks like it gets to the edge of the film.

The test shots with images show that there is a change in focus towards the left of the frame, this equating to the right hand of the film gate when in the camera.
I suspect that my packing of the lens assembly is either not stable or was not close enough to start with. I'm not sure how far out this is, it is only seen on the images which were set to infinity focus on a distant scene. So now i do need to find an "elegant" means to adjust the plane of the lens.

With so many things to fix, I could normally begin to lose interest in my Moskva 5s (I haven't even started on the other yet). however the images I have developed which haven't shown a fault are awesome 😱

This could be a really good tool for my pictorial/landscape work, well worth persevering with.

Any ideas welcome......
 
Hello fidget,

it really seems that this post is your own little blog. So far I knew Keith in OZ has a Moskwa5 too and I am the proudly owner of three samples. Every one has another flaw. The first has a quirky shutter, the second worn out struts, the third has a severly scrathed front lens. I had two of them for repair and CLA at Jurgen Kreckel in Saylorsburg,PA. He has done a very very good work but he can´t do miracles.

I´m admiring your braveness and skills. From my Moskwa with the worn struts I know, that if the front plate which is carrying the lens and shutter don´t snaps in correctly on both sides, you get partly misfocussed frames. Did you checked this already on you camera?

Cheers
George
 
It is probably the struts that are wrong. Do you have a Dremmel Mototool? If so, and if the problem is that the slotted slides are too short, you can grind away a bit of metal at the ends. However, if they are too long, I don't know what you could do about that.
 
Thanks for the ideas. It looks like the lens locks into place quite well, although nothing "snaps" into place. The struts end up quite rigid without play in them.

I think that I need a washer to fit on the nut side of the lens. This will allow me to place packing to bring the LHS side in, whilst the RHS has packing between the lens and plate, to pack it outwards. I think that if this were done well, it would be good. At the moment I have packed one side only, so the other is sort of floating around?
Can anyone suggest a source of a washer with a 32mm dia centre?

I have the other MOSKVA5 which has a similar problem but could have a parallel lens plate to start with.

I had no idea that these were just as much fun as their FSU 35mm RF cousins.

Dave..
 
fidget said:
Thanks for the ideas. It looks like the lens locks into place quite well, although nothing "snaps" into place. The struts end up quite rigid without play in them.

I think that I need a washer to fit on the nut side of the lens. This will allow me to place packing to bring the LHS side in, whilst the RHS has packing between the lens and plate, to pack it outwards. I think that if this were done well, it would be good. At the moment I have packed one side only, so the other is sort of floating around?
Can anyone suggest a source of a washer with a 32mm dia centre?

I have the other MOSKVA5 which has a similar problem but could have a parallel lens plate to start with.

I had no idea that these were just as much fun as their FSU 35mm RF cousins.

Dave..
Click to expand...

I have a pair of Moskva 2s. They don't seem to have that problem (maybe because they were allegedly made from Super Ikonta parts) but they did have a problem with diagonally tracking rangefinders. That was fixable, but a serious PITA. I don't know if it would work, but for filling in a small amount of the end of the slot that needs it, have you thought of using something like QuikSteel? http://www.dual-star.com/index2/Service/quiksteel_epoxy_putty.htm
 
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Hmm, FallisPhoto is onto something.
I tried my alignment measurement (straight edge and two steel rules) after I had erected the lens by letting it "self erect" with only small help from me. Then again after pushing the stays into place. They don't seem to move or snap into position, but the whole assembly is noticeably more rigid after this.

Measuring along a 2ft rule edge on the face of the bezel to the flat bed across the film rollers, shows that at 300mm from the lens centre the difference between the right and left is within say 1mm for the "helped" erection (I do hope that this reads ok!) and around 8-9mm for the self erected version. This is probably where the error had occurred in the photo that showed a difference.

I will need to make more accurate measurments, it's very difficult without help to get good readings.
But now I suspect that I should find out if it should "snap" into a locked position on erection.

Moskva 5 owners?

Dave......
 
fidget said:
...
But now I suspect that I should find out if it should "snap" into a locked position on erection.

Moskva 5 owners?

Dave......
Click to expand...

While most of my CLAd cameras will do this, it isn't a good idea to let them. If you do, then the repeated impacts can distort the metal enough over time that you get some play in there. Those struts are not tempered, after all, and are relatively soft metal. Better to ease it into position.
 
Thanks for even more info George, I had seen this one and used it to set up my RF.

FallisPhoto, thanks again for the input. I have dug out my Moskva5 (no1) This is in near mint cosmetic condition, but is awaiting a lens service (by my own hand!) so is stored at the moment. This clearly locks into a much more stable position (which may not be parallel to the film plane either) with very little help from me. It's much more positive than No2. So, the way forward may be clear......

At the moment I am getting ready for a weeks holiday in Cyprus (whoopee-doo!) and need to pack a folder I can rely upon, so the new-to-me Isolette II Solinar will be taken instead. This is not a second best, it seems to perform well also and I have managed to acquire a hood and 2 filters for it.

Happy days.....Dave.
 
fidget said:
At the moment I am getting ready for a weeks holiday in Cyprus (whoopee-doo!) and need to pack a folder I can rely upon, so the new-to-me Isolette II Solinar will be taken instead. This is not a second best, it seems to perform well also and I have managed to acquire a hood and 2 filters for it.

Happy days.....Dave.
Click to expand...

A very good camera, for its type. Once the bellows have been swapped out, and that green grease has been removed, I really like Isolettes and their Ansco equivalents. BTW, is this the same Isolette from your "Renewing and replacing bellows" post?
 
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Yes, it is the Isolette II that I replaced the bellows on and cleaned up the shutter and glass. A couple of test films show no probs other than a slight masking of one extreme side of the frame.....just got to get out and use it. (It doesn't do what the Moskva is capable of, but is very light and probably the right choice for the rucsack)
Dave.....
 
fidget said:
Yes, it is the Isolette II that I replaced the bellows on and cleaned up the shutter and glass. A couple of test films show no probs other than a slight masking of one extreme side of the frame.....just got to get out and use it. (It doesn't do what the Moskva is capable of, but is very light and probably the right choice for the rucsack)
Dave.....
Click to expand...

You ought to try an Isolette III, a Super Isolette or an Ansco Speedex Special R then. The Speedex Special R, in particular, can sometimes be found for $10 or $15. If you can get the elements apart, clean it up and change the bellows, it is a first-class shooter.
 
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