Vario-switar 16-100mmnot focusing to infinity

[Antoine Pret]

Hi all,

So i've checked all the older threads about focus issues on Bolex and lenses and here's my situation :

I have a Bolex H16 SB, wich I think is regular 16 and have tested the camera with four lenses :

• Vario switar compact 17-85 (Bayo Mount) : No problem
• Schneider RX 10mm (c mount) : No problem
• Canon TV zoom 16-100mm(c-mount): No problem
• and the Vario switar 16-100mm (Bayo Mount) : 

This one does not focus to infinity when it is set to it's wider end. When it's past the 25mm mark, it starts to get in focus.
When I stop down the lens a bit, it seems that it is a bit more in focus but it could be just an impression.

I've seen on older threads that if the lens what calibrated for s16, it would have a 1 mm focus problem on regular, but I've talked to the seller and he said the lens was used on a regular 16mm.
And the lens looks like new...

Now, the previous owner of the camera made a built light-meter, that I have removed but some elements of his modifications are still visible :

• They are screws on the viewfinder to remove the cover.
• There is a little thing behind the lens mount, which I think was the measurement cell.

I have checked the viewfinder carefully and Diopter setting is set in a correct position, so I think the camera is OK.

My guess would be that the focus flange of the vario switar needs to be adjusted and I was wondering if it has any settings or screws to calibrate it.
 

Edited May 11, 2022 by Antoine Pret
photos added

[Volker Bendt]

Hi Antoine,

the front lens group seems out of focus.

You find 4 tiny screws in the silver focus ring.

Zoom 100mm. focus set to infinity, loosen the srews a bit, hold the focus ring tight in infinity position, turn the lens front until the image sharpens.

Fix the srews and check at close focus.

Fine tuning until everything is perfect.

Good luck,

Volker

[Antoine Pret]

Thanks Volker, unfortunatly it didn't seem to be the problem. I've sent the lens to a very good bolex tech and even him had a hard time correcting it. I believe it is fixed now but it sure was a strange problem considering that the lens was almost brand new.