Optar 90/6.8 Flange focal distance ??

[gimenosaiz]

Hello!!

I'm looking for the flange focal distance of the Optar 90/6.8.

Any idea?

Thank you.
Kind regards,
Antonio

[Pere Casals]

Just measure it, focus it at infinite in a view camera (diafragm open), remove the lens and use a bare caliper to measure from the lens board outer surface to the GG...

or at night (room lights closed) just focus distant spot lights on the wall with max aperture in the lens, take an accurate measure of flange to wall distance, you may rest the lens on a DIY support to be placed on a table, to take the measurement, for example.

[gimenosaiz]

Just measure it, focus it at infinite in a view camera (diafragm open), remove the lens and use a bare caliper to measure from the lens board outer surface to the GG...

or at night (room lights closed) just focus distant spot lights on the wall with max aperture in the lens, take an accurate measure of flange to wall distance, you may rest the lens on a DIY support to be placed on a table, to take the measurement, for example.

Hi!

Wonderful. I was thinking about your first idea ... hahaha, I was looking for the caliper :-) But I'll try the second first !

Kind regards
Antonio