Rethread M42 to M39

[kershaw]

Hello there

I recently got a Zenit M3 SLR - beautifully made! I'm looking to use it but I don't have a lens. My L39 lenses don't fit - register issues. I do have an early m39 Helios which I use on another camera & I recently got (what I thought was) an identical lens off eBay. It isn't - it is an m42 but identical in every way except the mount is clearly a little thicker & seems to have been made identically to the m39 but just cut with a wider thread.

M39 SLR lenses seem much rarer & around 3-4 times the price on eBay at present.

My point: is it feasible to re-die (re-cut) the thread on my m42 lens or any other down to 39mm?
Suggestions, pointers & experiences with this process would be much appreciated.
Thanks
Kershaw

[martyn_bannister]

Isn't the register distance for M39 lenses different to M42? Wikipedia seems to think so.... This would mean you would have to re-cut the thread and adjust the register distance. Easier to buy the correct Helios/Industar lens?

[kershaw]

Thanks Martyn

I compared the register - appears identical.

m39 (non-L39) lenses appear much rarer & up to 4 times the price, certainly on eBay UK - I'll add that to the original posting BTW.

Best regards

[Minolfan]

The register is different, M39 is shorter. So I cannot use an M39 Mir 37mm on my DSLR, focusing farter than 2.70m. For my Jupiter-11 135mm the difference is not important. So I think Wiki is right with 45.2 vs 45.5.

[peterqd]

Wouldn't it be a more sensible idea to replace the M39 mount on the camera with M42? That way you could use all your M42 lenses and you'd definitely be able to get infinity focus. I had a look at my 3M and the mount is held with 4 screws. It looks fairly straightforward to drill 4 matching holes in an M42 adapter of some kind, of similar flange thickness to the M39 mount.

[kershaw]

Hello there

Thanks to you all for your thoughts, ideas & postings. I have had another good look at this & I find the following:

When the m39 Helios is inserted into the lens aperture of a Zenit 11 & held tight flush to the mount in the same position as the 'normal' m42 version it focuses (?& thereby registers presumably) absolutely perfectly & registers the distances correctly on the lens barrel - suggesting to me that, contrary to Wikipedia's assertions, there is no register difference, in respect of Zenit/Helios combination anyway. That is not of course to say it would per se register correctly on an m39 Zenit body but suggests surely this is likely.

I'd value any further ideas or suggestions anyone has.
[Thanks btw for the mount-swap suggestion - might be worth a try if all else fails.]
Best regards
Richard

[martinsmith99]

Which Zenit do you have? The early M39 mount Zenits were better (IMO) than the later ones.

I've picked up quite a few M39 lenses and they aren't that much dearer. Also look out for `A' lenses as the mounts can be changed; Jupiter 37A, Tair 11A etc.

[Attila]

Are you sure your camera is works fine ? Most of them not works at all or speeds are slow etc.

Don't waste your time to modify this camera , because now you see lenses on higher prices. There is plenty of better M42 camera than Zenit 3M and also plenty of better lenses.

Next lenses will be come on low price , just need to look.

If you still want to have one lens, let me know and give me an offer on an Industar 5cm red P M39 lens. I will sell it to you and if need one more body I can sell a working 3M body too.

[kershaw]

Thanks for your post Martin

I have 2 identical Zenit 3Ms

Richard

[kershaw]

Thanks for your post Atilla

No the camera does not work well - usual stuck shutter etc. I'd really like to get it working though. Thanks for the offer of a lens - I have very many good m42s & will try to make a mount for them first

Best regard
Richard

[geoffox23]

Wiki is correct.

Here is the Helios data, from Zenit
http://translate.googleusercontent.com/translate_c?hl=en&ie=UTF8&rurl=translate.google.com&sl=ru&tl=en&u=http://www.zenitcamera.com/archive/lenses/helios-44.html&usg=ALkJrhjdt9PrTMS4XC6sMOZyoTHN-eSIbw

[Kamerer]

[scsambrook]

Hi Kershaw! I think you're the first person I've ever seen say that a Zenith is 'beautifully made' If you don't have a lens on it I'm not sure that it's really worth putting much effort into trying to make it work properly. Attila's comments are pretty much spot on.

If you want to savour the pleasures of Soviet era SLR shooting, then Zenith E bodies can be bought for small change and often work tolerably well, although the top speed is likely to be not much different from the 1/250th setting. Well, that's true of many older SLRS, not just Zeniths.

The Zenith E, like the C and 3m, has the great advantage of plain ground glass screens which are excellent for use with long lenses of relatively small apertures. However, you'll see the top edge of the screen goes black because the mirror isn't really big enough (short and tapered). The E is better than the EM, and both are better than the TTL. The leather case for them also tends to snag on the body catch and unlock it, which fogs the film nicely before the back shuts again as you hold the camswera to take photos. That used to create lots of complaints - ! - but is easily solved by putting a piece of tape over the lip of the back catch.

Maybe we should have a new cult of "Zenitography" to rival "Lomography", eh?