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.
Contents
[hide]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 in microseconds; max exposure time is driven by frame rate 30Hz) 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 and to tighten them again when focussed. There are 3 of these tiny bolts - to access them, the lens needs to be removed from the camera enclosure.
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
