is it possible to use "land-based" macro len underwater ?

i was thinking of trying out macro lens like the

hoya macro lens underwater.

1. I am intenting to mount the lens on the external of the

underwater housing. as such there will be a slight water column

between the lens and the casing.

Is this workable?

2. I am aware of specialised underwater macro lens from Inon,

olympus and sea&sea. Was just wondering how this compares to these

"land-based" macro lens

Any advise much appreciated

"Land based" lenses are designed to work in air - water has a different index of refraction.

That's why you can put a "dry" macro lens on your camera INSIDE your housing - behind a flat port.

You need a specially designed lens to work in water.

HTH

James Wiseman

you are likely to find that the lens doesn't magnify as much in water as it does on land, and I think you are also likely to find that the edges are soft, because it's at the wrong distance from the camera's lens. In other words, it might act the way a cheap magnifying glass does on land, but what the heck, try it, as long as it's expendable (the metal ring will probably get too rusty to screw onto a land lens ever again).

Optical quality aside, unless the lens is purposly designed for U/W use, the seals between the lens elements (if there are any) are not likely to hold up to much pressure.

Thanks a lot everyone.

So i guess i must get a "wet-lens"

For my setup(olympus c40 and pt-012), i am left

with the following choices

1. Olympus PCU-01

2. Inon AD UCL-165AD

Any advise on either of these lens are

much appreciated

Interesting topic! The idea to use land camera close up lens for use underwater, thus a solution to an expensive purchase. Well just so happens I just returned from Bonaire on a macro photo trip. I had the same idea so I purchased a set of 67mm close up lens 1,2, & 4. I have an Olympus c3000z and an Olympus pt010 the threads are 67mm and it does work. I believe that the true lens made for underwater would work better. I would like to try both head to head. I shot with the no.4 it took some wonderful pictures. It had the advantages of going on underwater when I needed it.

Moreover, can these be attached and detached underwater?

Yep. For these less expensive housings these are wet attach lenses. You can screw them on underwater and take them off.

You can also drop them in several hunderd feet of water and lose them forever. About $300.00 gone.

That always freaked me out about my Inon lens. I used it on a rigdive in 600+ feet of water.

Cheers

James

Hi TommyG

Any pics from your recent trip to show?

I am very interested to see what the "land based" lens

can do underwater.

The usual complain is that the pic is soft around the

edges. Any problems with that?

Hi eagleray,

I will post a few as soon as I figure out how to do that. Yes the pictures are a little soft around the edges. I did like the results.

Hi TommyG

Was wondering was there a water column between the

macro lens and the underwater casing?

or was lens fittings water tight?

Hi eagleray,

Yes there is water between the housing and the lens. It uses the threads on the outside of the housing. I have been using the Olympus pt 010. The close up lens is not water tight.

to prevent loss of lenses etc, one can make the change-over inside a mesh bag (clipped to the BC). A short thin bungee will keep it out of the way when not in use.

Mike

Has anybody else tried this. I have a Ikelite housing for a Oly 4040 (6130.1).

Is the filter thread size the same as the PT-10 i.e. 67mm. I noticed that SUBAL make a selection of diopters but they are for dome ports, guess the optics are slightly different.

The thing that worries me the most is over threading the the port ring. Dose anybody know of what material it is made of on Ikelite hosuings ?