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).

Start windows manager

 startx

Start terminal. The ollowing commands are to be executed in x-terminal.

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