Hello Patrick.
Advance mechanism has been repaired too, viewing mirror has been custom cut, and most significant optical alignment was re-set.
About 9 upon 10 TLR cameras I receive have defective optical alignment, which I try to set within 0,02mm maximum deviation if possible.
I am lucky to own a factory Rolleiflex Autocollimator to do this.
It is the most critical thing if you want to have the best resolution from your lens, and usually it is not done by most of workshops.
Using a tool that is a reproduction of Rollei factory tool that I made on my lathe, I screw it in place of the front lens block.
then using a marble and a micrometer I measure the lens deviation on the four corners of the image frame
Using micro washer shims I then correct the front lens mount in order to have the results I need.
After that it's time to check with more accuracy on the Rolleiflex autocollimator, with lens removed. In B setting, full aperture, you must align a moving reticle to a static reticle in order to set the film plane. Then, you put an optical mirror on the shutter, and if the moving reticle is superposing to the static one, the optical alignment is perfect.
With this tool I can check the lens deviation, but also set the infinity on both lenses. After putting back the lens, I must find the point where the luminescent reticle is the sharpest. To minimize light diffraction, a green filter is put between the camera and the collimator in order to have an average light wavelength, it reduces reading errors.
on the first and last image you can see on the left a custom made collimator I machined using a XIXth century telescope from a theodolith, that is in the 600mm focal length range, very useful for checking infinity of wide angles, and on the right a Leitz collimator, originally designed for movie cameras, that I converted for both autocollimator and collimator. I can very quickly observe optical alignment and infinity setting on most small format cameras in a few minutes.
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