[Nick K.]

After Britain's Secret Seas showed fluorescent stuff (technical term) in St Abbs, I have been wondering how I can see the same. Last night I was poking about a bit on the internet and found people selling blue torches/filters and orange filter visors for considerable money, so I thought I should ask if anyone knows how I can do this on the cheap?

Many thanks in advance,

Nick K.

Britain's Secret Seas clip: BBC Two - Britain's Secret Seas, The Wild North, Night Dive - Marine Life
Company selling kit: Underwater Fluorescence for Sport Divers
Company selling kit: ultraviolet underwater light, underwater fluorescence, fluorescencia submarina

 

[bobdob]

I've been toying with the idea of making a UV torch for a while, although yet to do it. I came across these threads a few months ago. There's a couple of idea's for making your own.

Night dives with an ultraviolet lamp ("blacklight") - taking advantage of bio-fluorescence - BSAC Scuba Diving Forums

DIY LED and UV dive lights - Wetpixel :: Underwater Photography Forums

 

[LarsB]

Dear Nick K.,
dear bobdob,
you can find some ideas on how to use existing torches and how to modify them for fluorescence diving here: http://guest.engelschall.com/~sb/fluo-diving/#Equipment
When using blue LEDs (450-460 nm), you need an additional excitation filter in front of your torch's lens from Rosco (Permacolor Glass Dichroic Filters) of the type "Medium Red Blue" #34600/#4600.
And of course a yellow filter in front of your mask and camera. I use those from NightSea: http://www.nightsea.com/photoblue_ms.htm
You can also find a video of fluorescence diving in Dutch (cold!) waters here: http://guest.engelschall.com/~sb/fluo-diving/#Dreischor
Good luck!

 

[Nick K.]

FYI, the best resource I have found is Steffen Beyer's fluorescence web page: Steffen Beyer - Fluo-Diving

I have learnt that this will be too much trouble for me to do as a DIY project and that the commercially available ones cost hundreds of pounds more that I am willing to spend.

Better news is that there should be a much cheaper option available soon and I dare say that when there is, YD will be among first to know. Not spilling the beans on price and availability as I got told in a pm and I am not sure if it was in confidence.

 

[TerryH]

Might be worth playing with one of the Beaver type torches that use
the MR11 type bulbs.

You might be able to fit one of these
Toolstation > Clearance > Lamps > MR11 LED Lamp a bit

The other option is to not try and reinvent the wheel, so do the SL4 LED route and
get something like an old UK400 and low voltage high wattage UV in there with
a battey pack.

 

[LarsB]

I've done extensive testing with true UV, and it turned out that high-power UV LEDs are usually much more expensive and yet much less effective to excite fluorescence than blue LEDs (usually 450-460 nm).
The down side however is that with blue LEDs, you need additional filters, an excitation filter that cuts off everything above 500 nm and a yellow plastic filter in front of your mask and camera lens which cuts off everything below 500 nm.
That way you are sure to see only fluorescence and none of the blue excitation light, which would otherwise outshine the much weaker fluorescent light.

 

[LarsB]

By the way, I am selling this UV torch (2x Nichia NCSU033B 365 nm 6W, radiant flux avg. 816 mW, based on Underwater Kinetics UK Sunlight C4 eLED) for net cost price: 310 EUR (torch 115 EUR + LEDs 195 EUR) plus shipping plus Paypal fees 3.8% (if applicable) or bank transfer, without batteries (4x C).

 

[362436]

Slightly off topic but yet on topic...

Did you know that tonic water (as in G and T) fluoresces? It's the quinine apparently.

(I was demo-ing it to my Y9physics set last period on Friday...it was very hot and we were all tired...how I wished there could have been some G in it along with 'ice and a slice'! )

 

[LarsB]

By the way, see also this new site www.firedivegear.com (in particular the section about products) where you can find gear for fluorescence diving with a small budget.

 

[davebl]

For the St Abbs dive, we provided equipment, the camera filter is a minus Blue Filter, they are commonly available and appear yellow in colour, various manufacturers, we use Tiffen. Lars post above covers excitation, UV alone isn't so good. You need a Blue and UV pass filter in front of a broad spectrum source and it needs to be a Big lamp, Ours is 150W HMI source. It can be done much less expensively just run a few tests and see how you get on and what works best for you.

 

[horstartur]

We are performing HiTec Fluorescence since 2007. Tomorrow I will start for a 6 weeks stay in Dahab,Egypt to studey the coral reef with HighTech Fluorescence. To say it very briefly - effective Night dive fluorescence is not cheap, even when you are able to built torches like me. HiTec blue fluorescence LEDs are expensive. I have written a lot about my experiences on my homepage> Unbenanntes Dokument A selection of my results you can find on you tube > the links are also on my homepage. I have done already fluorescence and electron microscopy in the laboratory for 30 years - so the shift to "marine fluorescence" with own constructed torches was not extremely demanding.
However, don't hesitate to contact me if you have special questions. > horst.grunz et uni-due.de Have also a lookk on th Link NEW, whre I show our newest approach > torch simultaneously blue and white light with the same blue HiTec LEDs. I also will check my mail daily in Egypt. Cheers Horst

 

[LarsB]

BTW, everything you ever wanted to know about underwater fluorescence explained:

On The Rise: Fluorescence Night Dives - Background, Basics and Techniques

 

[Old Man]

I did a fluo-dive in Grenada earlier this year. Good fun and I wanted to pursue in the UK. The torch that I used was a UK C4eLED - one of the torches that I currently use for night diving. I was advised that it simply had a "blue light" bulb rather than the "normal" bulb. We also had to wear yellow mask filters. Since returning, I have been trying to locate an appropriate "blue light" bulb and mask filter. Any guidance where these may be obtained ? S'pose I could contact the dive centre for further info' if all else fails.