Air bubbles behind wet lens?

I am about to start diving with my first ever supplementary "wet lens". It is a wide-angle lens with 67mm threads that screws on in front of the front port of the video camera housing. I tested it in a pool today and was pleased by the sharpness and limited distortion.

Given that I mainly dive in less than crystal-clear seas, I think that I'll be using it most of the time. Because threading it on is a bit fiddly, to avoid cross-threading, I prefer to put it in place on board the boat and leave it on for the duration of the dive.

But the manual warns that "all bubbles between the supplementary wet lens and the housing port must be removed to avoid distortion problems".

What do you do?

Do you put the supplementary lens after submerging?

Do you have some technique for getting rid of all air bubbles?

Or, is this not a problem and the bubbles go away by themselves during descent?

All advice and suggestions gratefully received.

Regards

Peter

Peter,

Depending on the brand of housing you are mounting your lens on, may have small holes around the port mount threaded area to vent bubbles.

With Ikelite housings, as you state, I always recommend shooters thread and mount the lens before entering the water.

Once submerged look into the front lens and "fan" your hand under the lens attachment area. You should see any air bubbles vent out the small holes.

Hope this helps!

dhaas

Bubbles mostly came out with pressure as you go down, but if some of them remains just remove and replace wet lens, this must solve it.

Once submerged look into the front lens and "fan" your hand under the lens attachment area. You should see any air bubbles vent out the small holes.

It is worth pointing out that this "fanning" technique is worth doing for ports as well as wetmount lenses. I make it a habit of removing the small bubbles from the face of my dome port this way. Never rub the lens or port surface, just fan water across it.

Steve,

I DO fan bubbles away from my dSLR housing ports, too, but as far as worrying about rubbing?

I thought the same as you, being afraid of abrasion.......Until I saw Howard Hall do it repeatedly on some National Geographic (or may it was in the IMAX film?) with his multi-thousand dollar High Definition camera system

I think the trick is not to have really rough gloves, and do it gently. Water will fill in an amazing amount of scratches, dings, etc.

YMMV!

dhaas

Thanks guys for the input.

I'll start the dive with the supplementary lens screwed in place and use the fanning technique across the lens surface and near the small holes between the supplementary lens and the housing port.

Regards

Peter