LTM adapter doesn't work

[peter_chiappini]

Hello, I bought a LTM lens to M42 body adapter, but it doesn't allow

you to focus on objects farther than a few inches away. I am

assuming that because the distance from the rear element to the film

plane is different on Pentax Spotmatic than with my Canon IVSB that

the lens can't get close enough to the film to focus at infinity.

At first I thought that I had mounted it wrong, but the lens is

securely and snuggly fastened to the camera. Is there a way to make

this adapter work, or is it essentially worthless for normal

photographic use. Does anyone know of a LTM lens/M42 body

combination that would work with this adapter? I suppose it could be

useful as a macro adapter, but it seems unlikely that these would

have been manufactured for that purpose. I also saw schneider

enlarging lens to LTM camera body adapters for sale on eb*y; this

seems ridiculous because all of the schneider enlarging lenses that

I know of are LTM, and the one I have fits perfectly onto my Canon

IVSB.

[al_kaplan1]

Many older Schneider enlarger lenses are "Schneider thread" which is about 25mm diameter. These were usually secured to the unthreaded lensboard with a "lock nut" which came with the lens. Since some enlargers don't have lensboards but are Leica thread (39mm) they make adapters.

 

You're quite right that standard Leica thread mount camera lenses are of little use beyond close-up photography on a Pentax mount body. The exeption would be the old "short mount" lenses designed to use on the Visoflex reflex housing. Those lenses would actually require a short extension tube to work correctly on your Pentax body. Probably the most common use of a simple female Leica to male Pentax adapter would be to mount an emlarging lens, perhaps a 135mm, on a bellows attachment. This would give you infinity to extreme close focus capability.

[andy_piper2]

You can fit Pentax SLR lenses onto a Leica screw (or M) mount camera and scale-focus them all the way to infinity.

 

You cannot (as you've discovered) fit rangefinder lenses onto an SLR and use them for anything but macro close-ups, for the reasons you describe. ANY LTM lens/M42 adapter will produce this same result. And yes, they were essentially intended for macro work, often with a bellows. And often with an enlarging lens with an LTM thread.

 

Exception - some older (pre-1970) longer (90mm/135mm) RF lenses have removable lens heads that can be mounted, via SHORT adapter/focus rings, onto SLR bodies and still reach infinity. Making the adapter shallow compensates for the extra depth of the SLR body vs. the rangefinder. Examples: big ol' stovepipe 90 Summicron, 135 Hektors(?)/Elmars/Tele-Elmars.

 

I don't know if anyone made one to fit LEICA lens heads onto PENTAX bodies - but over the past 45 years someone probably did at some time.

[laika]

"is it essentially worthless for normal photographic use"

 

Nope, it sounds like you have a M39 to M42 adaptor made for adapting lenses made for the early Russian (and others?) SLR's (M39) to fit the later more standard M42 mount. Using rangefinder glass will only work for close-up. You need an adaptor with a glass element to correct the lens-film distance and them I think it will multiply the focal length like a tele-converter.