How do I know the lightbulb I am buying is UV-filtered?

Question

Thanks to Rob Hoare's advice on cobbling together my own "overhead scanner", I would like to purchase extra lighting that I can use to illuminate documents as I photograph them. I would like to make sure they are UV-filtered (according to Fortiter's recommendation) to minimize lighting damage as they are photographed.

Is it possible to tell from the packaging/type of lightbulb if they are UV-filtered, or is it necessary that I buy an external UV filter regardless of the illumination I purchase?

Answer 1

If you need to illuminate documents that you are "scanning" in such a manner, and you wish to filter UV light, a sheet of your average picture framing glass between the bulb and the document should filter out most UV light. If you are intent on filtering out as much of it as you can, you could pick up a small piece of multi-coated museum glass, which will transmit more visible light and filter out more UV light. Keep in mind museum glass is far more expensive than standard framing glass.

You will probably also want to cover the glass sheet with some thin paper in order to diffuse the light, as the comment by Gene states. You will definitely want to diffuse the light to better illuminate the subject you are photographing.

Answer 2

I imagine that manufacturers of light sources that reduce the UV emitted would label their products prominently in order to justify the higher price. You might begin by searching on the trade name UVILEX™ 390 Z, but I am sure that there are others.