I recently purchased a 1866 Voigtlander f4 lens and trying to figure out the focus on it. To me it looks complete it has rear and front lens optics. I did the wall test and image came into focus around 11.5 in (measured from waterhouse slot to wall)
When i mounted the lens to my 8x10 Century Studio with 5x7 GG back image would only come into focus when rear standard was about 1-2in from front standard. (Very sharp image very shallow DOF) Pretty much smushed the bellows. subject about 3 ft away Why is this?

I would think by the wall tests this should be the same scenario with image on GG when bellows is stretched. Kinda thrown off by this. I tried backing up to about 8ft of subject and it was even more OOF.


Any ideas? Is this lens a paper weight? Lens optics reversed? Missing a lens?



Thanks,
Michael