210mm Heliar Question

[Dwayne Martin]

I recently picked up a21cm Heliar and its mounted in a copal #3, the rear cell actually stops the aperture blades from moving because the glass reaches too far into the back of the shutter. I obviously need to place a spacer of some kind so my question is how far can I go? I don't know what the spacing was when it was in a barrel mount if it was a barrel, it could have been mounted in a compound shutter I suppose. Mine is the post war coated variety. As the cells become farther from one and other does this change the focal length of the lens. Is a few mm one way or the other negligible?

Thanks in advance for any help.
SE

 

[Jim Noel]

Put the lens backin the barrel and measure the length from back to front. then put it in the shutter and shim it until the distanceis exactly the same.

 

[Luis-F-S]

Or you could send it to SKG and have him mount it correctly and be done with it.

 

[shutterfinger]

This 1964 Voigtlander catalog http://www.cameraeccentric.com/html/info/voigtlander_2.html lists the 21cm Heilar as being in barrel or Compound III.
The Compur Shutter repair manual http://www.suaudeau.eu/memo/rep/compur-repair/02-05.html lists the dimensions for Compound shutters on back side of page 2 of the Specifications.

 

[John Koehrer]

The question you need to ask is does the lens focus as it is? Or, will it focus as the groups are separated?