Speed Graphic top mounted Graflex rangfinder beamsplitter replacement

[BySumbergsStache]

My beamsplitter glass and mirror are hazy and needs replacement. Old posts all point to edmunds, but they seem to have been replaced by science direct, which has no 50/50 beamsplitter.

I'm looking at the different glass from surplus shed, and I'm wondering which would be the most suitable. There is a 70/30 and a 50/50 and several different colors.

In addition, what mirror would you recommend?

 

[shutterfinger]

Rangefinders use a 50/50 beamsplitter. The Edmund Scientific beamsplitter is no longer available. Edmund Optics http://www.edmundoptics.com/optics/beamsplitters/plate-beamsplitters/plate-beamsplitters/45316/
replacement. Cut the beamsplitter to the correct dimensions with a glass cutter. The coated side should face the front of the camera. If the replacement is thinner than the original shim between the frame and the mirror to position the frint surface at the same position as the original. Calibrate the rangefinder according to the instructions in this service manual http://www.southbristolviews.com/pics/Graphic/manual-pdf/servicemanual.pdf . The instructions on page 6 say to use a target at least 500 feet away, it is a misprint, it should be 5000 feet away or further.

The moveable mirror should clean easily with regular glass cleaner. If it is loosing its silvering or is severely scratched then replace it with a piece of mirror of similar thickness cut to size. It can be a front surface mirror but a rear surface will work equally well.

 

[BySumbergsStache]

I don't really plan on fixing other rangefinders, so I hate to spent $35 on a tiny piece of glass. Has anyone tried the surplus 30/70 or 50/50 reflective beamsplitter glass? Does beamsplitter glass for rangefinders have any special requirements? I would think that pretty much any type of half silvered mirror would work.

 

[shutterfinger]

Use 50/50 beamsplitter only regardless of source. A 30/70 will have a hard to see second image. Color does not matter.
Do not use a wavy mirror if you want reliable operation.
I got my last supply off ebay.