F1G2 optical modifications

[Bill W]

Some notes and experiments modifying the F1G2 optically, just to see what happens.

Tool / handy parts list - will be updated as we go..

• T5 security driver - required
• Micro USB extender cable - handy

First a quick summary of taking it apart.  See also the original thread https://www.eevblog.com/forum/thermal-imaging/new-flir-products/msg750181/#msg750181 although this teardown has different objectives

1 - separate plastic halves, they are stuck togther with tape in the join.  Unplug battery which is stuck to the rear part


2 - remove copper foil.  The F1G2 is not short on bits of tape and glue 
Then undo the 5 Torx T5 security screws.  the PCB should now come free, and brings the USB connector PCB with it, attached with more tape !

4 - Peel off the foil, cut it and reattach the temperature sensor.  While this has broken the thermal link to the lens/shutter unit, everything from here in will make temperature readings inaccurate


5 - unclip shutter unit

Now ready to play      

[Bill W]

So a few points on what we now have:


The lens can be turned to refocus the camera.  It is secured with a tiny bit of glue, but readily releases with tweezers on the castellations.

Note: in hindsight best to mark where it was set to if you want to get back there easily !!

It does not need to go far as this is a very short focal length lens  Half a turn could be plenty for PCB work.  if you undo it too far the lens will foul the shutter, so best to test this before reassembly with the lever noted.

Having removed most of the copper tape, the unit will now go back into the housing quite easily and it seems easiest to refix the USB connector in place.

Bill

[Bill W]

Some close up images with Georg's App +, the big benefit of that is the full sensor resolution and losing the visual edge detection overlay which is particularly useless when close up.

Soldering iron, cooling down to fit in temperature span:

Power inductor

FPGA


Bill

[Bill W]

A bit about the F1G2 lens.

This is quoted as 56° field of view on this 160 x 120 12u sensor.
This gives it a focal length of just 1.8mm, which ties in with the quoted aperture and it's size.




When considering refocusing this lens the school optics equation matters:

1/f = 1/u + 1/v  (f = focal length, u = image distance, v = object distance)

If we assume it is at infinity as delivered then:
u = f = 1.8mm

If we want to come down to 50mm:

1/1.8 = 1/u + 1/50
u = 1.87mm

It only needs to move out by 0.07mm !

[Fraser]

Thanks for this Bill.

I will be following your adventures with the F1G2 with interest.

If you need to create a new FFC flag Frenky was using a CCTV camera IR filter actuator that I recommended for the task. He was using it in front of a SEEK cameras lens. You may well have better approaches to that requirement though.

For anyone else wanting such a DIY FFC shutter, please take a look at Frenky's post on this forum. I will provide the URL later. I recommended the use of the mechanism that moves the IR filter in and out of the optical path on a night/day camera. It is a solenoid operated lens holder. The IR lens may be painted Matt black or replaced with a more suitable material. The mechanisms are available via eBay from China for a couple of Dollars or so. Be aware that a polarity reversal is needed to change the position of the mechanism though. Not difficult to provide though.

Fraser

[Fraser]

The link to Frenky's thread on adding a better FFC shutter to the SEEK camera.

https://www.eevblog.com/forum/thermal-imaging/seek-thermal-hardware-modification-to-improve-image-quality/

Fraser