View Full Version : PMW-350K Backfocus Tweeking?


Thierry Humeau
February 24th, 2010, 07:20 PM
The back focus adjustment on my PMW-350K stock lens is a bit off. Is there any way to tweek this?

Thierry.

Charles Newcomb
February 24th, 2010, 08:07 PM
The back focus adjustment on my PMW-350K stock lens is a bit off. Is there any way to tweek this?

Thierry.

http://www.dvinfo.net/forum/sony-xdcam-ex-cinealta/472010-lack-back-focus-adjustment-pmw350-fujinon-lens.html

Or, you could just put it back in the box and send it to me. I'll be happy to take it off your hands. :)

Thierry Humeau
February 25th, 2010, 07:51 AM
Charles, there is nothing in that thread that explains what to do if the backfocus is off. I suppose there is some kind of advanced or service menu that allows to address this?

Thierry.

Felix Halter
February 25th, 2010, 08:39 AM
Check your manual under "Adjusting the Flange Focal Length" about page 40 on the PDF.

Thierry Humeau
February 25th, 2010, 10:46 AM
Thanks Felix, found the Flange Automatic adjustment button underneath the lens grip. Also, there is a Flange adjustment item in the Maintenance/Lens menu that does the same thing.

Thierry.

Daniel Epstein
February 25th, 2010, 11:53 AM
So Thierry did the button work on the adjustment? How accurate do you think it is. Does it care what you have the lens pointed at? Can it be fooled? How often do you have use it? Thanks for the info

Thierry Humeau
February 25th, 2010, 12:33 PM
You have to start by fully zooming in a standard back focus adjustment chart placed about 10 feet from the camera (camera comes with a back focus chart), push the Flange adjust button underneath the lens and let the camera do its magic. It takes a a few seconds and the adjustment seems perfect. I dont think this needs to be repeated often if any.

Enjoy.

Thierry.

Paul Cronin
February 25th, 2010, 02:12 PM
Page 42 in the manual. "Adjusting the Flange Focal Length" Make sure you don't do this in too bright a places since it opens the iris fully each time.

I have had to do this three times now with all the lens switching I have been doing. Will be interesting with the ZA17x and HJ17x lens I will be testing this weekend to see how much closer I can get the back focus on both of those knowing they it will stay were i set them. Then go back to the stock lens and see how much it moves each time.