I can see the light at the end of the tunnel...
I count myself as very fortunate to have found a webcam, that works in oil, on my first try... but it sure lead to disappointment in the others!
The HP Camera could not focus (it was auto focus with no manual override)
The Raspberry pi camera has a very small lens case and too few threads to focus. I even added the lens frame from my borked logitech cam but it was seated just a little to far off the sensor or something. (it was very close to being focused, but not close enough)
Also, sadly, after 9 months, either directly in, or at least wet with, oil, my little logitech that could, no longer can. It still puts out a signal (that seems to be affected by the light going in) but it is just blocks of color.
So I must adapt!
I hot glued the Raspberry pi camera to the acrylic cap sealing it. Then I glued a small acrylic cylinder around it. Next I poured in a clear epoxy till it covered the whole board.
From the front.
Here is my new 1/4" E-Tube with thick endcaps.
Here is the Raspberry pi camera Module. Inside is the Raspberry and camera, voltage converter and Homeplug adapter.
On the left: Testing before sealing up. Middle: Sealed up and pouring the oil. (lessons learned and applied) Right: All done! Complete with questionably useful, convection powered, cooling tube! The return fitting has a short hose inside, piping the ocean cooled oil directly to the bottom! Hooray!
Testing confirms, with happy leds (and a video stream), that all is working properly. (it is possible that the focus was set a little short. It will certainly be fine for the job at hand, but I will have to think hard about who i can blame for this)
I left it on for 1 hour and 20 mins and it was still running. There was some warmth in parts but not too hot. I would not say the cooling tube was activated, but if it was left for a longer period of time, and had nice cold ocean water all around it, I'm betting it would positively trickle through that tube!
Now that I have the two camera enabled modules set up, plus the light modules, I have only to:
Assemble the rig
Test everything with batteries
File the 2 additional e-tube ends
Test cable to see how long I can get it whilst still having a signal.
Set up ad-hoc slip ring(s)
Set up measuring wheel
Fill Battery Packs with oil.
Test everything with oil filled battery packs
Rent a boat
Other things I have forgotten but will hopefully remember before setting out. :D
Then pray for calm weather...
Or Google it.