Lens mount L39 & M39

Are bayonet lens mounts L39 and L39 the same?
Thanks for any help
John.

 

There both screw, metric 39 x1mm pitch

M bayonet Fit is just that

 

thanks Trev silly me! I did mean to say screw lens mounts L39 & M39 are
they the same?
I must put my mind in gear first before engaging keyboard!
Regards.
John.

 

Both have the same thread, however they are two different mounts,
because the lens flange to film distance differs substantially.

M39 mount was used by the manufacturers of the early Soviet SLRs among
others. The lens flange therefore had to clear the reflex mirror.

L39 mount was used by Leica and other rangefinder camera
manufacturers. There is no mirror box so the lens flange could be
placed much closer to the film.

M39 and L39 lenses will mount on cameras designed for either mount.
However, you will not be able to obtain focus if you use the lenses on
the wrong type of camera.

In other words, L39 rangefinder lenses will not obtain focus on M39
SLR cameras, except for close macro workand M39 lenses for SLRs will
not obtain focus on L39 rangefinder cameras at all.

Beware the very cheap M39 to M42 adapters offered on eBay. They are
designed to mount M39 SLR lenses on M42 mount SLRs. Any L39
rangefinder lens used with an M39 to M42 adapter on an SLR will only
be good for close macro work.

 

Tony Polson wrote:


thank you tony, great help

 

M39 is 39mm diameter and 1mm pitch. L39 is also 39mm
diameter but is 26TPI (threads per inch) pitch.

The difference is small but can (and does) make some lenses
difficult to mount on some bodies. In particular most
Russian lenses are M39 whether intended for use on SLRs or
RF cameras.

 

They don't Tony. The difference is slight but real.

M39 is 39mm x 1mm, L39 is 39mm x 26TPI.

 

Thanks, John. I didn't know that.

But between the two of us, I think we have the subject covered. ;-)

Thanks again.

 

[SNIP]

Presumably they could if fitted with an appropriate length extension tube?
Not very useful in general though, not being coupled to the rangefinder.


Peter

 

Yes, of course. I did not feel a need to mention that. ;-)

True, however I use an M42 20mm Carl Zeiss Flektogon on my Leica M
bodies without problems. Obviously there is sufficient depth of field
to cover minor scale focusing errors.