wide(r) angle view for your old ATC2K action cam

Step 4 Optional : make the lense work under water

Basically, you are done if all you want is shoot film above water.

But if you want a sharp image under water, you need to do some more.

The lenses in this Jelly Lense are designed based on the assumption that
the light always goes from air to plastic and vice versa. The light is bent slightly dfferent on water-to-plastic boundaries. this results in a fuzzy image under water.

What needs to be done is to put a clear window in front of the jelly lense. I did this by simply gluing
a bit of polycarbonate (i think..) to the front of the jelly lense. I used a solvent based glue.
First time around (yes, that is why you buy two lenses..) I used CA,. but this attacks the polycarbonate, giving it a white hazy coat and ruining your work. Do not use CA.
between the jelly lense and the actual ATC2K there should also be air, not water. we come to that
with the re-assembly of the ATC2K.

in the photo, the outer two pieces of plastic are just to protect the lense/window combo from the
clamp. you can still see the CA-induced white haze on the upper piece of plastic.