L39 or M39? for my Zorki 4k

[Gerald Costello]

Totally hooked on my recently purchased Zorki 4k. So much so that I am thinking of adding a lens or two with a turret viewfinder. I am a touch confused about whether an M39 screw mount lens will fit and couple correctly with the rangefinder. I have been reading up on the internet but there seems to be conflicting advice on the compatibility of m39 screw fit lenses to this model which is the original Leica L39 screw fit thread.

Hoping that I'll get the definitive answer here.

Great site by the way!


Gerald

 

[Roger Hicks]

L39 and M39 SHOULD be identical: 39mm x 26 tpi (turns per inch -- remember Leitz was a microscope company and RMS threads, the first standardized threads in the world, are imperial).

A few manufacturers' lenses are however said to be 39mm x 1mm (25.4 tpi) and others reputedly have a different thread angle.

On the bright side, I have not yet (in 40+ years) encountered either a Leica screw camera or an FSU lens that were incompatible on this ground.

Cheers,

R.

 

[steverett]

My zorki lenses all mount and focus fine on my leicas, and vice-versa.

 

[wolves3012]

Just to point out that L39 usually means "Leica" 39mm i.e. an RF lens whereas M39 usually means M39 screw (same as the more common M42 but a bit smaller!). M39 lenses are for cameras like the early Zenits. They have no coupling cam and are designed not for RF bodies but for SLR bodies. As such they can be fitted but they're nothing more than a dearer and more fragile body-cap!

 

[payasam]

There should be no trouble. Sellers generally add "Leica" or "Zorki" to their descriptions of lenses. As for the turret finder, if it's a KMZ product you should not get the version made for Kievs.

 

[Spyderman]

Sellers generally add "Leica" or "Zorki" to their descriptions of lenses

Yes, but they are often wrong, and often write something like "Zorki, leica, zenit" to further confuse the buyer 😀

Your best bet is to search the internet and find if the lens you want to buy was made for Zorki/FED/ Leica screw mount.

For example Jupiter-9. you can find these in L39 (Zorki), M39 (Zenit) and M42 (Zenit, Pentax). Similar Jupiter-11. Industar-61 was made in L/Z version for SLR and L/D version for RF (Z = SLR, D = RF).

 

[Seele]

The "L" in "L39" simply means "Leica", i.e. complying to Leica's standard which is in fact far from standard.

When talking about a screw thead, you need to specify three specifications: diameter (as in the diameter of the "male" part), the pitch, and the thread profile: Leica's screw mount is a weird mixture of standards, the diameter is 39mm, pitch is 26TPI, and thread profile is Whitworth, if memory serves.

The "M" as in "M42", describing the "Praktica screw mount" means its thread profile is the ISO standard, which was inherited from German standard, so, "M42X1" tells you the complete specification of this mount. "M39" does not really mean much, really.