Focusing the video lens

This page describes how to focus FUJINON video camera lens in DFNEXT camera systems (Point grey / FLIR digital cameras) using freeture video capture software.

-- Stop the freeture SW running as service --

systemctl stop freeture.service

-- Run freeture in to display currently captured video live on screen --

Login as user which is not root locally (keyboard + monitor + mouse needed).

Switch user to root may be needed

su - root

Run freeture, zoom in, set window with video full screen or enlarge it to se the focus is sharp:

freeture -m 2 --display -g GAIN -e EXPOSURE_TIME

Use GAIN (0 .. 29.99) and EXPOSURE time (0-33000 us) appropriate for current lighting conditions.

In full scrren/enlarged mode, the image update may be slow or freeze. This is related to the CPU load - transferring image from video camera over USB and scaling it to screen buffer. Restart the above commend if that happens and zoom in only partially or zoom 1:1, but shrink the window.

A tiny hex key (size TBD - 0.8 mm or 0.6 mm) is needed to loosen the video lens focus fixing bolts. There are 3 of these tiny bolts - to access them, the lens needs to be removed from the camera box.

Note: Set the F-stop (mechanical lever on the lens) to full open, check if the focus is sharp as with f/1.8 or f/2.0. If yes, keep the wide open setting. If not, stop down to f/1.8 or f/2.0.

-- Stop freeture --

By pressing [Esc] in the terminal window where it was started.

-- Start the freeture SW running as service again --

systemctl start freeture.service