Tag Archives: beamsplitter repair

Leica IIIf Beamsplitter Replace

I’ve given my 1953 Leica IIIf “red dial” a CLA, or Clean Lube and Adjust and now I need to replace the half-mirror, or beamsplitter in the rangefinder. The beamsplitter gives the double image that moves back and forth as you focus the lens until the two images become one, then it is focused. On older cameras, the beamsplitter, which is a half-mirror, or partially silvered so it is transparent as well as reflective, looses some it’s reflectiveness and is hard to focus.

After getting the top off (see the procedure here) I was able to get to the rangefinder.

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remove the end cap by simply prying off. It is held on with lacquer

 

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remove the three screws on top of the RF (circled)

 

After I got the beamsplitter housing bracket loose, I noticed there were two objects in the way to prevent it from sliding out…

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pry up the focus cam, it comes up quite easily. there is a screw from inside the film chamber protruding up (circled) loosen it.

 

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loosen but don’t remove the screw holding the RF housing. just enough for the mirror housing to clear the screw.

 

Now the beamsplitter housing can slip out

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here the beamsplitter housing is out, take note of how it goes back in.

 

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the half-mirror beamsplitter is glued on with lacquer(?) simply pry it off.

 

I got my beamsplitter pre-cut from a fellow on eBay (nobbysparrow) and it was only $10. I say only because it is way worth it, not buying some stock and trying to cut it myself. let alone send it off to have it professionally done for around $110 or more.

Plus it is a modern process (the silvering) from Japan and less likely to rub off and fade through time.

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gently clean the old glue from the housing. be careful, it is soft brass.

 

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here is the new beamsplitter half-mirror glued onto the housing. I used Elmer’s white glue. never use CA, or super glue as the fumes fog lenses and mirrors permanently.

 

It really isn’t hard to do this yourself. follow my instructions on how to remove the top plate and you can have a new fresh beamsplitter in your Leica for a fraction of the cost and a few hours, not weeks or months