Thanks Ken,
I can't get away with not having a filter as I've removed the glass covering the sensor.
if I leave it open, moisture could cause a short, so I'll need a layer of glass.
I'll see if I can get a piece of clear glass cut and use a UV/IR filter at the end of the nosepiece.
Can I use an LP filter as the L filter?
Transmission curve for the LPS-P2 filter
http://www.sciencecenter.net/hutech/idas/filtdata.htm
It looks like it covers the lower and upper ends of a normal L filter, but the added bonus is that it cuts off or reduces the Light pollution wavelengths as well.
Curve for astronomik LRGB filters
http://www.astro.uni-bonn.de/~mischa...nomik_lrgb.png
Will there be a discernible difference between a 12bit and 14bit dslr for DSO's?
I'm hoping to try it tonight if I can get the glass cut.
Cheers
Alistair