Convex Lenses, Light Concentration, Glass
This has to deal with burning glasses(concentrating light
to burn). My friends and I noticed that using a burning glass
outside works fine, but as soon as you try to use it behind glass,
it is ineffective. We were wondering if it is the UV light from the
sun that causes it to burn things, and if so, if pure UV light
could be concentrated to a greater effect. I have searched for the
answer and could not find anything helpful. Thank you for your time
UV light should not be the issue. Glass and plastic are fairly opaque to UV, so
a lens will not transmit UV to focus it.
In my experience, magnifying glasses work just fine to concentrate light coming
through a window. So without knowing more about your set-up, I cannot say why
it does not work for you.
Richard Barrans, Ph.D., M.Ed.
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Update: June 2012