A small river: underwater infrared

[Andy Perrin]

Hmm. Water is going to absorb UV pretty well, especially with dissolved matter in it too. Expect really long exposure times! Your underwater case needs to transmit UV well also.

[nfoto]

Very clear inland waters do transmit UV to >1m depth, but mostly UV will be absorbed by dissolved humic matter.

 

Add to that the filters which probably leak some IR, a lens not transmitting UV all that well, plus the barrier represented by the glass or plastic port of the underwater housing, and UV underwater appears to be a huge challenge to record. Perhaps a UV-capable flash can add the needed illumination? Many years ago I shot underwater IR on IE ('aerochrome') film using strobes at several m depth. At the time I wasn't into UV, though.

[ins13]

Andy Perrin, Birna, yes, there are many difficulties and obstacles with this, but must try anyway. Perhaps - even most likely - it will not work. But I can't know for sure until I try. At least 365 nm passes through plastic of my underwater bag. And it is a huge plus :)

I have Ennalyt 35 3,5. I'll choose a small shallow river. And the UV goes through the water better - or at least not worse - than infrared.

 

I had modified and tested the flash YN560III. not in water. I had tested it for fluorescence. Not like. I have trouble with the flash: it doesn't give enough light at the right distance nearly 0,5m

left flash, right flash+flashlight

[Shane]

My favorite is the "mermaid" image, a self portrait with some mystery.

[ins13]

Shane, thanks a lot for the comment! :)

[otoien]

Very nice underwater IR, perhaps the first I have seen. Well done with the over-under captures, they are not easy to position.

 

I concur about the "mermaid" image standing out with its mystery.

[ins13]

Thank you!! This summer I'll even take pictures of mermaids again. and Mer-man :D

[Andrea B.]

My plan for this summer is underwater ultraviolet photography.

 

UV does play some kind of role for aquatic flora & fauna as we have all no doubt seen in various nature films and writings. So it will be very interesting to see what you can discover.

 

One of our members here Reed Curry wrote a book about trout fishing and the trout's UV vision:

The New Scientific Angling - Trout and Ultraviolet Vision

I ran across Reed's book years ago (2010 maybe?) before I ever knew him and long before we started UVP. I do not go fishing for trout, but I thought is was such a unique UV related book that I simply had to have it.

 

Here is only one of the many references about fish vision and UV:

The Contribution of Ultraviolet and Short-Wavelength Sensitive Cone Mechanisms to Color Vision in Rainbow Trout

by Coughlin D.J. & Hawryshyn C.W.

[ins13]

It's obviously a very good book.

Thanks for the links! I will read and try to study about the ultraviolet vision of fishes on the internet. And maybe i'll buy this book too..