Are diopters really necessary for WA work?

Hi all,

I just purchased my Aquatica D200 housing and was reading the lens and port compatibility chart which recommends diopters with certain lens'. From all the research I've done, it seems that diopters are only beneficial for close up work and would not be beneficial for shooting large animals such as sharks, rays, whales ect... Am I correct on this?

Thanks,

Matt

I forgot to mention, I'll only be doing wide angle work on big fish for now.

Underwater the dome port acts like a Negative diopter. So you need a postative diopter to counteract this.

If the lens is not able to focus closer than 2x the dome diameter then without a diopter the lens will not be able to focus on anything at any distance underwater.

If the lens can focus closer than 2x the dome diameter a diopter is not absolutely required to focus but still may imporove sharpness.

Be advised that if you put the lens in the port and try it out above water - it will focus just fine. But when you submerge it, it may not be able to focus at all!

If you want to post your lens and port combo here, perhaps we can make some recommendations?

Cheers

James

Thanks for the replies guys. The port will be an Aquatica 8" WA dome and the lenses will most likely be a Nikon 12-24 and 18-35. According to Aquatica, no diopter is needed for either. I may also use an 18-70 which Aquatica states will need a +4 diopter. I will probably be trying out a Magic Filter also. Not sure if that will have any effect.

James, what part of Houston are you in? I lived their for 8 years and worked as a commercial diver out of Freeport. Awesome city!

Later,

Matt

Hi Matt,

I live in the Houston Heights. I'm a deepwater engineer (pipeline).

I used the Aquatica 8" dome w/ the 12-24 and got decent results. For extreme close up wideangle, I'd recommend trying a +1 or +2 diopter.

With the 18-35, I'd STRONGLY recommend you try it w/ a diopter. It's not in the same league as the others and will def. benefit.

Cheers

James

Thanks James,

I was thinking that +4 may be a little extreme. I'll give it a shot and see what happens. I love this whole DSLR and housing thing. So much to learn and so much money to spend:)

Later,

Matt

James is probably right, but I have found that +3 D works better than +2 D with the NIkon 12-24 and a Nexus 160 dome, which is, admittedly, a bit smaller than the Aquatica dome. I would suggest experimenting, if you can borrow a couple of 77mm dioptres. In the end I bought B+W dioptres because they have a very low profile but seem tougher than some other manufacturers' lenses.

There are lots of postings about the 12-24mm because it's very sensitive to dome/extension/dioptre combinations, and easily gives poor results underwater...

However, it can do this:

Tim

B)

Thanks for the advice Tim. I'll play around with it and see what happens.

Take care,

Matt