T3D Re: underwater housings

[john bercovitz <bercov@xxxxxxxxxxx>]

>Does anyone have any experience at all?  Stereo or not?

I don't have any experience with it but I do have experience with
high pressure; it's part of my job.

>My plan is to build one out of plexiglas.  The stuff is easy to cut and
>glue, and will withstand any amount of pressure if thick enough.

That's a nice choice - it will allow you to diagnose problems visually.
Polycarbonate fails more gracefully than acrylic, and cuts and joins
about the same, but it does have a color cast so you would have to put 
optical ports on the front of the housing.  Probably not a bad idea
anyway.

>Maybe my biggest questions are about water-tight controls and maximum
>depth.  I assume I will build a special camera that has motorized
>functions, and a controlled depth of field.

For watertight controls, I would recommend magnetically-operated switches.
No seals to fail.

For maximum depth calculations, I would recommend "Roark's Formulas
for Stress and Strain", McGraw-Hill, any edition.  If you find it slow 
going, I can help you with the formulas in that book.

John B


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