Difference between revisions of "Focus adjustment 393"

Latest revision as of 15:56, 2 October 2020

Description

internal use

Regular SFE

1. used on big the Xeon PC - 192.168.0.6
2. restore from /home/elphel/test_focusing/default.conf-xml
3. quick get&show
4. find grid (if error - increase/decrease exposure using the 'camera settings' button - the range is 2.5-5.0 ms - rerun steps 3. and 4.)
5. no-move measure
6. show PSF
7. adjust screws
8. repeat from 5. until good (if some PSF spots are missing - repeat from 4.)

Setup before using ImageJ Aberration Calibration plugin

Parts

• Assembled SFE without lens and without IR-cut filter (can be with the filter if the target lens is different)
• M12 adapter
• 2 spacers: 5mm and 4.7mm (shaved off 0.3mm (made from 5mm spacer) for optimal adjustment)
• Lens N125B04530W with IR-cut filter. If the target lens is different, still use this one for adjustment then replace. Wrap the thread of the lens with the teflon tape for better thread fitting - 2 layers is enough. When screwing in make sure the tape does not get in the optical path. Screw in the lens until full stop.

Fig.2a SFE parts

Fig.2b Sensor teflon spacers

• Focus adjustment screws - do not overtighten initially. Later, right before starting the procedure when the camera is against the pattern - turn it on, while in jpeg open the control interface and adjust the screws for the best manual focus (do not apply too much force).

Fig.3 Focus adjustment screws

Assembled setup

• Take a longer cable - at least 100mm
• Connect to port 0
• Set the camera address to 192.168.0.38

# temporary (ssh will freeze, connect from another window)
~# ifconfig eth0 192.168.0.38

# permanently (reboot required)
edit /etc/network/interfaces

• Make sure the power supply provides the right voltage - 12V or 48V. If possible install PoE compatible power board - 10386.

Fig.4 Assembled focusing setup

Pattern

• Use the wallpaper pattern.
• Notice the distance from the pattern.
• Notice the height of the camera. Position the camera to point to the center of imaginary rectangle where laser pointers mark the corners. Actually the center is marked with a blue masking tape triangle.

Fig.5 Tripod placement

Fig.6 Tripod closeup

• Make sure all 4 lasers are pointing in the right spots - "manual laser pointers" yellow button in the imagej plugin

Fig.7 Laser spot markings

• Turn off the room lights.
• Turn on the patter lights if they are not on automatically.
• No need to close the garage door.
• Now proceed with regular_SFE instructions.