>>2982043maybe he misremembered and thought of UV - optical glass starts heavily cutting off ultraviolet around 350nm and for anything shorter you need quartz or fluorite optics. Long far infrared also transmits poorly or at all, but those ranges are far beyond any CCD's wavelength range.
There is a plethora of very comprehensive and interesting ir digital/film photography websites out there, I urge you to do some research beyond /p/.
[uv+~800nm ir on an old digicam with a poor uv/ir filter through wood's glass from a tanning bed heater]
