Mir-1 take-apart for clean & lube?

[rumplestiltskin]

I bought a Mir-1 (37mm ƒ2.8) and expect to receive it soon. I know it has some issues regarding stiff focus and aperture adjustment so I'm looking to do a disassembly for a clean & lube job. Here are some photos:

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This is a 39mm screw-mount (I have the 39>42 ring). I did some searching on YouTube and found a couple of videos but I thought some kind soul up here at mu43 might have done this procedure already and has some advice and/or can point me to the best video on this topic.

Thanks!

Barry

 

[rumplestiltskin]

Anyone??

 

[ex machina]

I was lucky enough to find an m42 version at a flea market in good working condition for $5, haven't had a chance to shoot with it, yet. Love that yours is the Grand Prix model -- congrats, good luck with the refurb and look forward to seeing some shots from it.

 

[rumplestiltskin]

Worst case: I have a short helicoid and adjustable aperture I can fit between the lens and my Panny. Obviously, I hope to have the lens working properly instead.

 

[rumplestiltskin]

Lens arrived and I'll really need to clean that helicoid. I had a scare regarding the aperture as it did not seem to adjust to anything smaller than fully open; but I realized after a minute or so that this is a "preset" aperture so the ring inboard of the aperture ring adjust the aperture down to whatever I've "preset" as the largest (numerically) f-stop. I can actually leave the aperture at f16 (as that ring is a bit stiff) but use the "preset adjuster ring" (for want of a better phrase) to control the aperture in a click-less manner.

The M39>M42 ring poses a slight problem, however. It's a bit too tall (from one end of the thread to the other) as it keeps the lens from seating fully in my M42>µ4/3 adapter (helicoid or standard), therefore no infinity focus. I guess I'll have to figure a way to grind down the ring about 1/16" or so. (Other suggestions welcomed; perhaps there's a source for these shorter rings?)

I have no shots worth posting yet but, even wide open, it appears to be fairly sharp. Beware my birdhouse shot coming tomorrow during daylight hours.

 

[ex machina]

The M39>M42 ring poses a slight problem, however. It's a bit too tall (from one end of the thread to the other) as it keeps the lens from seating fully in my M42>µ4/3 adapter (helicoid or standard), therefore no infinity focus. I guess I'll have to figure a way to grind down the ring about 1/16" or so. (Other suggestions welcomed; perhaps there's a source for these shorter rings?)

How about just skipping the adaptor ring and getting an m39>m43 adaptor?

 

[rumplestiltskin]

How about just skipping the adaptor ring and getting an m39>m43 adaptor?

Ah, good suggestion but, unfortunately, such an adapter expects I'm using a lens designed for a Leica rangefinder camera so the depth of the adapter is too short.

 

[rumplestiltskin]

Did a closer examination of the adapter ring I have and it is -not- impacting the depth to which the Mir can be screwed into the M42 helicoid I have. I'll have to take another look at this in the morning when I'm not so tired and I have some daylight so I can make sense of this.

 

[rumplestiltskin]

I created a Showcase thread for this Mir-1. The lens will not focus to infinity with the standard M42>µ4/3 adapter (helicoid or otherwise). I'll see what sort of extension tube + shorter helicoid will permit infinity. I will continue to use a separate helicoid for focusing as the Mir only focuses down to about 27" with its internal helicoid and that's just too far away to be as useful as I think this lens will be. I think the quality of the glass is surprisingly good considering the provenance and condition; some marring of the front element through careless handling and you can see the rear of the lens has some bending of the metal shield(?) around the rear element. Once I cleared off the dust back there, the glass was pristine.

I found a 9mm (I think) section of m42 extension tube and, when I used that, the 12-19 M42 helicoid, and the M42>µ43 adapter, I was able to focus to infinity and as close as 6". I believe I'll be able to use a 14mm-26mm helicoid and still achieve infinity focus all the way in to ???". So it can be a nice macro lens. I'll probably forego cleaning the helicoid in the lens and just gorilla snot it into place so I don't move it accidentally. Likewise, the aperture preset ring is notchy and too stiff so I think a little more silicone seal there would do the job of keeping it preset to the max (ƒ16). The ring behind it that actually stops down the lens is very easy to turn Essentially, I'm using this lens as if it were from an enlarger. I can live with that as the cost was minimal and the lens is pretty darn nice.