Infared light - lenses and ink

[derekbeau]

is it possible to read infared ink with human eyes. I have seen lenses for cameras but can't find anything for eyes. If so, where is informaiton on this


thakns

 

[Doc Al]

invisible ink

is it possible to read infared ink with human eyes. I have seen lenses for cameras but can't find anything for eyes. If so, where is informaiton on this

I've heard of "invisible" inks that fluoresce when illuminated with infrared light. (Similar to UV invisible ink, but on the other side of the visible range.) I assume the flouresence is visible--otherwise what's the point? Do a search on invisible inks.

 

[chroot]

Digital cameras and camcorders that use CCDs can detect infrared light (though some cameras specifically include an IR filter somewhere in the optical path to thwart this). However, your eye cannot see infrared light, and there's no way to make it. The best you can do is to use a device like a CCD chip to record the IR and reproduce the image in visible light.

- Warren