Fixing back focus

MikeWilkinson

MikeWilkinson

Veteran
Is there a proper way to calibrate the back focus on fuji lenses? (like the T17x5BRM4)

One of our DVCPRO cameras (AJ-D410A) goes out of focus on the zoom out, and I know how to tweak it, but want to kow if there's a better way than to test and check...

Thanks!

(If there is a better place to post this query, moderator, feel free!)
 
Hi Mike,

Make a print of this siemens star and set it up in front of the camera just slightly further away then the closet focus mark on the footage scale of the lens. Zoom to the longest focal length and focus on the target. Now zoom wide and adjust the back focus for sharpest image. Repeat operation to see if there is any change in the focus at the tele end. Twice should do it.

Chuck

http://en.wikipedia.org/wiki/Image:Siemens_star.svg
 
And do it again from time to time, some cameras are very sensitive to the ambiant temperature and their own temperature when you have it working a long time.. No panic it is easy to performe!
 
also keep your iris open as much as possible and stay far back. try and use a hires monitor if possible even a tv
 
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