slad
Newbie
Has anyone used a Kenko tele-converter for thr M? Saw one on ebay and was curious about how goood it was or wasn't.
Wonder if that's for use with the Visoflex? Hard to imagine a teleconverter working on an RF camera...
BTW, welcome to RFF, slad! 
Just looked up the eBay auction... wild, never would have believed it, but Komura did it, along with a 80-270 zoom finder!
Just looked up the eBay auction... wild, never would have believed it, but Komura did it, along with a 80-270 zoom finder!
Graybeard
Longtime IIIf User
Probably the best use of a 2X Extender would be to create a fast effective 100mm from a f2 50mm lens. With any longer focal length you run into difficulties framing the image with the on-board or an auxiliary viewfinder.
I speak from some related experience. I have an adapter that permits me to mount M42 (Pentax) lenses on a screw mount Leica (or an M-Leica with the screw to bayonet adaptor). Focus is by using the scale on the lens barrel.
This actually works pretty well with wide angle lenses such as a Soligor 24mm and a 16mm fisheye. I have also attempted to use the adapter with longer lenses, outdoors, generally with distant subjects with the focus at infinity. With lenses greater than 200mm, the viewfinder image is so small you're never quite certain where the camera is really pointed. A subject one thought was nicely centered is often off to one side or poorly framed.
Even with the camera mounted on a tripod, parallax errors between the lens and an auxiliary viewfinder really can be a problem.
I speak from some related experience. I have an adapter that permits me to mount M42 (Pentax) lenses on a screw mount Leica (or an M-Leica with the screw to bayonet adaptor). Focus is by using the scale on the lens barrel.
This actually works pretty well with wide angle lenses such as a Soligor 24mm and a 16mm fisheye. I have also attempted to use the adapter with longer lenses, outdoors, generally with distant subjects with the focus at infinity. With lenses greater than 200mm, the viewfinder image is so small you're never quite certain where the camera is really pointed. A subject one thought was nicely centered is often off to one side or poorly framed.
Even with the camera mounted on a tripod, parallax errors between the lens and an auxiliary viewfinder really can be a problem.
slad
Newbie
Thanks, Doug. And you are right it's a Komura. I have a 90mm Elmarit F:2.8. Being able to use it as a 180mm with the 2x would be nice. Every once in a while I find myself wanting just a little more reach. Leitz did make a 180mm with eyes for the M but this lens was a prototype and never reached production.