Jack Berner

8 hours ago, Dom Jaeger said:

I service and repair cine lenses, I don't shoot with them much, although I deal with client's footage all the time.

The zoom is parfocal, as all cine zooms are, subject to age-related wear. If a zoom has had a lot of use without regular maintenance the zoom cams can be worn, potentially causing focus to drop out mid-range. That's something a tech could diagnose.  But if you've seen tests that were soft it's probably more likely due to the back-focus being off (or the camera flange depth being out), which causes the focus to drift as you zoom out to the wide end. Or operator error, as you say - some people don't realize they should focus cine zooms at the long end (where it's most critical) and zoom out to the focal length desired. If they eye-focus at the wide end or mid-range, and then try to zoom in, it will very likely look soft.

The 10-100 does breathe a bit. Since the 12-120 is the same lens with just a 1.2x extender fitted to the back, it breathes just the same.

Thanks for sharing your expertise, Dom

3 hours ago, Dom Jaeger said:

The original 10-100 is T2, the S16 factory converted 11-110 is T2.2 (a third of a stop slower), and the Optex 12-120 version is T2.4 (about half a stop slower). 

Thank you Dom! I hadn’t realized the 11-110mm was just a factory conversion of the old N16 10-100mm.

Have you shot very much with the 12-120mm Optex? Saw a test video on YouTube that made the lens seem very much not parafocal, but maybe that was just operator error. I’ve also read that the 10-100 breathes pretty badly. Is the same true for the 12-120?

Hi Alec,

still available? What’s the stop loss from the optex?

Thanks,

Jack

Hi Tim,

I'm wondering if you're still sitting on this amazingly customized F55. I'm in the market for one, and now feel like I can't live without this top plate. Feel free to reach out via email - jbernercamera@gmail.com

Thanks,

Jack