On Fri, 01 May 2015 08:33:36 -0700, wrote:

[Snip]

I wish they were quartz because of the toughness and UV transmission.
The filter I removed was a two piece affair. At first I wondered why
two pieces of glass were cemented together and I thought maybe it was
for strength. But I think it is because the clear piece of glass is to
filter out UV. This would be good because CCD sensors also see into
the UV spectrum a ways and I would like to get some pictures of
reflected UV from flowers and such. Tonight I will be installing the
glass and doing any adjusting of the sensor location that may need to
be done. Tomorrow night I hope it will all be back tohether so I can
try it out at a bonfire.
Eric

Perhaps a source of quarts flats would from quartz crystals used in
electronic devices. e.g. RF oscillators, computer clock control and
such. I think CCD sensors are more sensitive to IR than UV. In any
case UV doesn't transmit well through regular glass lens.

Cheers