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Author Topic: Photography with UV Light  (Read 1549 times)

alexlee

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Photography with UV Light
« on: 07 Oct 16, 13:02 »
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  • Hi all photography masters!!  :P   

    I have a noob question which i hope all of you can help me with. What's the difference between a 365 nm UV light and a 410 nm UV light? Am I right to say  that 410 nm UV is the usual purple light we always see? I also realize that 365 nm UV is yellow in colour. Why is it so? How do we use these lights for underwater photography?

    Thank you very much for any advice i can get!!

    Alex

    siaokao

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    Re: Photography with UV Light
    « Reply #1 on: 07 Oct 16, 16:00 »
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  • I know nuts about shooting UV photos underwater.  But I do know our eyes are not good at seeing UV light in wavelength described above.  Very few device can produce 'pure' UV light (single specific wavelength), therefore, those colours you are seeing are 'stray' lights and may not be a good representation of the main UV emission from your light source.  Meaning those colours really do not mean anything.  The main reason why anyone would like to use UV light for photoshoot is because these UV light excites certain dyes to make them 'glow' thus more interesting colour effect on subjects.
    So they call it a 'FACT' coz someone made some statements on a 'FACT SHEET'? hummm...

    FishEye

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    Re: Photography with UV Light
    « Reply #2 on: 07 Oct 16, 16:55 »
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  • I'm not an expert in the field but for 'UV' underwater photography you are better off using a blue light with a yellow filter over your lens.

    I have dabbled a little in the past. Take a look at FireDiveGear. (http://firedivegear.com/)

    Photos taken below were using their equipment. It is technically not UV photography, it is Fluoro photography.

    https://www.facebook.com/nickshallcrossphotography/photos/a.608754679162431.1073741834.301800926524476/658665637504668/?type=3&theater

    https://www.facebook.com/nickshallcrossphotography/photos/a.608754679162431.1073741834.301800926524476/658045337566698/?type=3&theater

    snikrs

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    Re: Photography with UV Light
    « Reply #3 on: 08 Oct 16, 20:27 »
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  • Played a little with fluorescent diving when I was in Australia. I'm by no means an expert and only completed a couple of fluoro dives. However, the dive centre was excellent and gave a very good and detailed crash course on the science behind it. Do take what's written here with a pinch of salt. Here's what I roughly remember from that brief talk:

    The light used in fluoro diving isn't a UV black light, but rather it's a blue light at 420nm wavelength, which is very close to the ultraviolet (UV) band. The ultraviolet band consists of wavelengths 380nm to 10nm. 365nm is actually a true UV light. UV light is not visible to the human eye. The reason we have to use a yellow filter to actually see fluorescence during fluoro dives, is to filter out the blue light (420nm) that is visible to us. Without the filter, everything will just be seen as bluish, but when the yellow filter negates the blue light, the resulting fluorescence of the critter can be seen clearly.

    If you're going for fluoro pictures, the 410nm light would be what you're looking for. 365nm wouldn't work, technically, since we can't see it, and there's lesser excitation at those wavelengths.

    EDIT: Oh yes, the filters/lenses of some fluoro/uv lights may seem yellow, but they actually output blue or UV light. The glass is what's known as a dichroic filter. An example, this is for the strobes - http://www.ikelite.com/accessories/4069.1-dichroic-excitation-filter.html
    « Last Edit: 08 Oct 16, 20:35 by snikrs »

    alexlee

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    Re: Photography with UV Light
    « Reply #4 on: 03 Nov 16, 10:47 »
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  • Hey hey... ;D

    Thanks all for the advice!!  :) :)