Christopher Trice

Chris, Thank you for your input. My lens does not have the aspheron knob (or I could not find it) but in all honesty lens adjustment is not something I would feel comfortable doing. I think my plan of action will be to get the film developed and confirm the issue and then find someone to service it. Part of the reason for this rationale is that I like to know something is broken before I go about fixing it. Thank you again. I'll let you know how it all turns out. CGT

Thank you everyone for your responses. I'm not sure if the back focus is correctly adjusted but I should find out soon as I shot three rolls today - one of which tested the technique I described above. To be clear, I wasn't attempting to zoom while shooting. I just wanted to set the focus while zoomed in, zoom out and then shoot. Thanks again!

Thank you Robert, The reason I started down this line of thought is the following quote from the manual. "Manual variation of the focal length or power-zooming from 16 to 100mm, without affecting either relative aperture or picture sharpness." (p.1) Now, this could be translated as meaning parfocal or just another example of oddly worded manual-speak from Bolex.

Hello, I have recently picked up a Kern POE 16-100mm 100 lens and am wondering if the lens is parfocal? Do be clear, does the lens maintain focus if I zoom in and out? I'm curious because I find it often much easier to zoom all the way in, focus and then zoom out. Thank you.