While perusing one of my favorite sites, buzzfeed.com, I ran across a set of pictures taken by photographer Cara Phillips (http://cara-phillips.com) using Ultraviolet light.
The pictures on Cara's site are taken using a method called reflected UV. The subject is illuminated by UV lamps that are coated with a filter that blocks all visible light. The filters are made of quartz (fused silica) or quartz and fluorite. While regular lamps have filters that allow only the "long" UV light to pass through them, these filters only allow the lower, usually unseen, light rays in the UV spectrum to pass through while blocking "regular" UV light.
UV photography can also be accomplished by using a special lens UV filter (for example the Kodak Wratten 18A filter) which blocks all visible light and only allows the light in the UV spectrum through the lens. Below are a couple of examples of when and how each type of UV photography can be used.
Reflected UV photography is often used by dermatologists to show a client how their skin may of already been damaged by exposure to the sun. The pictures below taken with the UV light exposes the imperfections in the skin that a dermatologist can then use to suggest skin treatments that may be necessary. The first two pictures are taken with regular light, not utilizing any UV technology. The third picture taken with reflected UV light exposes the damage the sun has already done represented by the slight mottling on her skin:
(photo courtesy http://www.skincarephysicians.com)
UV photography can also be accomplished by using a special filter (the Kodak Wratten 18A Filter for example). The filter works by blocking all visible light and only allowing light in the UV spectrum to pass through the lens. An example of a photo taken with this type of filter is below. Police agencies can use filtered UV photographs to look for bruises or marks on the skin that are no longer apparent to the naked eye or do not show any longer in 'regular" photographs. The picture on the left below shows no sign of bruising, but when a picture is taken using a UV filter, a bruise is seen on the child's forehead and possibly his nose:
(photo courtesy of http://www.crime-scene-investigator.net)
If you choose to try your hand at UV photography it can be expensive. Almost all photography lens and filters are produced to BLOCK UV rays. Finding the right equipment to allow you to take UV pictures can be an uphill and expensive battle.
Click on this link to go to the original web page containing the photographs taken by Cara Phillips that piqued my curiosity of UV photography: http://www.buzzfeed.com/mathieus/ultraviolet-portraits-8q4
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