lens underwater questions

Hi all!

Have some queries with regard to underwater lenses. I'm still quite new to these.

Do you attach them before you enter the water or after you enter?

Is the arrangement air tight as in water will not creep into the space between the housing and the lens? If so, will there be a differential pressure when you go deeper? Will this damage the lens?

Cheers for any answers!

Most add-on lenses are outside the housing, with water between the housing port and the back element of the lens. Most also are vented in this area, so that if you attach before entering the water, the water will enter anyway. Just make sure that there are no air pockets before you shoot.

Some add-ons are added to the camera and inside the housing. Obviously, you will have to make sure that the port will accomodate the extra glass. The Nikon wide angle for the 5000 comes to mind.

The advantage to the in water add-ons is that you can add or remove as subjects and conditions change.

I just received my INON wide angle lense and I am now wonder what I would do with the lense when I take it off underwater to shoot macro.

Is there a special case you can purchase? Seems like you would risk scratching the lens by just putting it in your BC pocket.

Any Advice?

That's what dive buddies are for:D

Here is what I came up with:

What you see in the photos are the following all threaded together:

67mm Filter stack cap.

67mm to 72mm step up ring.

72mm to 67mm step down ring.

67mm to 72mm step up ring.

72mm to 67mm step down ring.

I drilled a hole in the center of the filter stack cap and used an allen bolt to bolt it to my tray. I also used epoxy on the theads to make sure they wouldn't unscrew. You might be asking why I did ste step up/step down twice. The reason is to give it depth so the allen bolt would touch the back element of the lens. It really works great. All I want now is a soft neoprene cover for the lens (I hate using the plastic one with thick gloves) so I can have it easily protected while u/w.

Very clever. I love it. My dive buddy will love it, too!

Off to the camera store as soon as I get back from Bonaire.

The filter stack caps might be hard to find (my local camera stores didn't have them) so you can get them at

http://photofilter.net/.