Leica IIIf rangefinder spot dimness

[Dez]

I agree with ZorkiKat about the glue. The cyanoacrylate is very strong and sets too quickly. The mirror must be positioned exactly, and if you get it wrong, it is good to be able to remove it easily. I believe the type of glue used for building model airplanes is of the type ZorkiKat recommends. Contact cement or silicone will be quite flexible, but may not position the mirror accurately.

In taking the top off, I use an egg carton, with its 12 little compartments, to put the parts removed; that way there is no confusion about which screw goes where. In removing the rangefinder lens surrounds, the one closest to the rewind just screws out, but the one close to the winder is more complicated: First the outer bezel is unscrewed, then the friction-fit rotating lens that sets vertical alignment is pried out (no screw threads). Make a small mark on it at the top so you will know how to align it when you reassemble it. Then an inner ring needs to be unscrewed, or it will be difficult to remove the top. You do not need to remove the lens mount.
When removing the eyepiece at the back, usually one of the two lenses will come out. Be very careful not to lose it. I am not certain if the two lenses are the same, but I always make sure not to interchange them.

Good luck, and have a very good Christmas!
Dez

 

[zauhar]

The use of the word 'beamsplitter' is correct, it is the term a physicist would use for a half-silvered mirror in this configuration. In some optical setups (such as making a hologram) the half-silvered mirror is used to split a source beam into two parts, here it is being used "in reverse" to combine two source beams into one.

Just trying to dust off my physics degree. ;-)

My IIIf was purchased from YouXin, he had already installed a new beamsplitter. It is pretty bright, I can generally focus the IIIf almost has easily as my M3.

Best of luck in getting your camera where you want it to be.

Randy

 

[traveler_101]

To the OP: Don't get me wrong. I think it is admirable that you are willing to try to fix it yourself and it is good to hear that you have some experience repairing cameras. Best of luck!!!!

 

[Silme Ea]

Finally I could spare a day and my camera wasn't loaded, so I decided to replace the rangefinder mirror. 🙂

I used mainly these two guides:
http://www.mediajoy.com/en/lrc/refresh/index.html
http://www.flickr.com/photos/8487951@N05/sets/72157625135357333/with/5123594880/

It turned out to be quite easy to replace the mirror, I think anybody who knows its way with a screwdriver can accomplish it. For me the hard part was to readjust the rangefinder, but only because I had never done it before 🙂

As for the results, rangefinder spot is definitely better now! Although I still don't like the fuzziness of spot's borders, I've enjoyed the process and learnt quite a lot about how to disassemble those little Barnack's 🙂

Thanks all for your help and encouragement!

 

[johannielscom]

An eBay seller named Nobbysparrow sells the beamsplitters in proper Barnack size.

The best instruction on how to DIY is this: http://jelabs.blogspot.nl/2012/06/replacing-beam-splitter-mirror-in.html

I replaced the beamsplitter in my early Leica II about a year ago, it was a 20-min job. I'd never done one before.

It made a big difference and the little Leica II is my most-loved camera now.


EDIT: re-aligning the RF is explained at this page: http://jay.fedka.com/index_files/Page422.htm

 

[Silme Ea]

An eBay seller named Nobbysparrow sells the beamsplitters in proper Barnack size.

I second that, very good stuff he offers. Now my Leica has a japanese mirror 🙂

The best instruction on how to DIY is this: http://jelabs.blogspot.nl/2012/06/replacing-beam-splitter-mirror-in.html

Nice guide, alas I didn't spot it earlier 🙂