Originally posted by RioRico Let's distinguish between three types of lenses with 39mm threads (I've heard of a 4th type but never seen it.)
1) LTM. These have a register (flange-focal distance) of 28.8mm. They can't reach infinity focus on a PK camera.
2) M39. These have the same 45.46mm register as M42 or PK. I use M39-M42 plus M42-PK adapters to fit these.
3) L39. These are enlarger lenses (ELs) with no 'register' as such. ELs longer than about 60mm can focus to infinity on PK cameras with the right extension.
One of the worst eBay feelings comes when one bids on multiple copies of a lens -- and wins them all -- and finds that they're LTM, not M39. Duh. Oh yeah, ANOTHER learning experience.
Thanx for your very informative reply. I am still confused though on the compatibility of the lens I bought.
Here is a eBay link of the lens I purchased
Leica Leitz Summarit 50 mm f/1.5 Screw Mount Lens Wetzlar Professional Cleaned | eBay
From Ken Rockwell's website on screw mount camera review, Ken said this
LEICA IIIf (1950-1957) It's half way down in the section of
COMPATIBILITY
"Screw mount lenses are also called M39 by Leica, as well as L mount, LTM (Leica Thread Mount), 39mm x 1.0mm thread, Leica Thread, and probably even other appellations."
So he basically stated they are all the same where they probably have different flange focal distance he wan't aware of.
How do I tell which one of the LTM or M39 my lens belongs to ( I assume it's not an L39)
I am not a very technical guy and just need to know if I should keep the lens or sell it.
Again all the help and info here are really appreciated.
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