How to adjust a rangefinder without too much hassle ....
May I tell you the trick I use to adjust rangefinders ?
I put the camera on a table facing a wall and shine though the viewfinder window
(where there is normally the photographer's eye) a little laser pointer used at
If the rangefinder is correctly set (and the lens focused on the wall) the two
spots (one from the viewing window, the other from the rangefinder window) will
met on the wall and produce only one spot. If the RF is not aligned, horizontally,
you'll find 2 spots, on the same horizontal line, and if it is vertically, the
two spots will be on a vertical line. If they're at 45° apart, this means that both the horizontal and vertical are at fault.
This permits you to use both hands to tweak the adjustments, and as this setup
is bright and clear, it makes an easy tool to check/realign the RF.
The main problem here is to stick the laser to the viewfinder, but as a photographer you already own 4 to 6 arms... to help ;-)
Similar in pricipal to the Kalrt Focuspot, which uses a light beam through the rangefinder for focusing in the dark. Come to think of it, that would probably work using your method with, say, an Argus brick, wouldn't you think? The Focuspot was supposedly designed for photographing the inside of aircraft wings and such and was widely used on Speed Graphics.
Another method is to place an X and a + on a piece of card or paper horizontally separated by exactly the rangefinder's baseline. Set the lens at infinity and your X/+ alignment card at a comfortable working distance parallel with the film plane and adjust the rangefinder until the X and + align. This method doesn't lend itself to setting the near range.
A computer CADD program and a decent printer can generate a very accurate target.
I assumed they were set at infinity such as a Mamiya 7/7II --I would like to check my M2 that I recently picked up as well as my M5.