I am an underwater cinematographer looking to construct two arrays of very bright UV Leds, to be housed in machined watertight housings, in order to film flourescence in reef fish and corals in the Western Pacific. I am not an idiot, but perhaps someone could let me know which UV LEDs would work for me, and where is an inexpensive source- I want something roughly equivalent in spectrum and brightness to the LEDs in the INOVA X5 UV. Thanks- Dirk Winebarger toadboy65@earthlink.net
Your best source for piles of cheap UV LEDs are no doubt going to be Hong Kong, but I don't think that's really what you want to do. UV tubes (AKA 'blacklight tubes') are several times more efficient. And have much longer life spans (UV LEDs have epoxy degradation problems, which get worse as you drive them harder, that limit useful light output).
And at the relatively low pressures you're dealing with, I'd have guessed a plastic case would have been the call?
While I'm far from an expert on glowing fish, if they are anything like minerals, the narrow spectrum of UV from LEDs may not make them all glow. Minerals react to UV differently, some glow under short wave UV, some long wave UV, and others in the mid frequency UV. If fish are anything like this, with different fish glowing under UV wave lengths, then you might want to consider something like the UK Light Cannon with a UV filter added to it. The UK is dive rated to 500ft, and runs about $160.00. It's 10 watt HID lamp produces 500 lumens of light and contains a fair amount of UV. The UK also comes with filters which spread the light out to an even flood for video use. You would however need to locate an acceptable UV filter for your intended purpose. I would think two of these lights would provide plenty of illumination for you with a very low cost.
Anyone out there know what UV spectrums make fish glow? [img]/ubbthreads/images/graemlins/thinking.gif[/img]
I would suggest an array of Luxeon Royal Blue LED's interspersed with some Shark 6W UV LED's. Nichia is close I believe in bringing their 2W UV LED's to market as well. I believe they have a lower pass band than the Shark. I was recently on Maui for a month and had a Shark mounted in a light that would have served UW but I never did get a chance to do a night dive to check it out. [img]/ubbthreads/images/graemlins/frown.gif[/img] I believe you will want to pick a port material that will allow for maximum UV transmission. Sounds like a cool project! [img]/ubbthreads/images/graemlins/thumbsup.gif[/img]
I think I would be remiss if I didn't make the following comment/ observation. I wanted to see the coral as well as any critters that would fluoresce but I was also a bit concerned. I have read where some divers will put UV blocking filters on their bright incandescent dive lights so that they don't harm or damage the sea life. I would assume that the coral and sea life would be capable of taking UV exposure comperable to levels they are exposed to from the sun but I have no idea what those levels are or how they would compare to an artificial source like you are proposing? Could the levels required for filming present serious risk to the sea life?
Thanks for the responses. I have used the inova X-5 UV (bagged), and got pretty good results. Of course to achieve the volume of light I need, I would have to use at least 8 of those. does anyone know where I could get equivalent LEDs? I am not sure they are true UV, or if they are just violet bleeding into the UV spectrum.They are, however, super bright. I could not get specific info from their website. Oh- What I want to do is nowhere near sterilizing levels of UV, I do not believe there will be any ill effects on the marine life.
You shouldn't need to bag an X5, they are supposed to be waterproof to 150'. Putting it in a bag is probably affecting your results since most plastics are very poor transmitters of UV.
There is a special filter kit for the UK Light Cannon for doing this kind of photography.
[ QUOTE ] toadboy said:
Thanks for the responses. I have used the inova X-5 UV (bagged), and got pretty good results. Of course to achieve the volume of light I need, I would have to use at least 8 of those. does anyone know where I could get equivalent LEDs?
[/ QUOTE ]
I thought I already did......yup, I sure did....didja miss it?
LED selection for Underwater Flood
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