Luminance Filter

[adamsp123]

I read an article somewhere that made the statement that some people doing LRGB imaging do not use the L filter in order to get some IR data as CCDs are sensitive in IR.

Does anyone here do this?

Another thing do any of you use a "standard" LP filter (with IR/UV block) for Luminance instead of the supplied one that comes with the set.

cheers Pete

[Ben Ritchie]

With refractors it depends on the colour correction, many apochromats start to diverge in the far red so you need IR blocking to keep tight stars.

However, some - the FSQ springs to mind - are well corrected to 900-1000nm, and can make use of the near-IR sensitivity of some CCDs (e.g. the Kodak KAF series are very red-sensitive, so there's still a lot of signal)

[beamish]

I've had more success in capturing detail using IR742 for "L" rather than the "L" filter, which I was lead to believe is effectively an IR/UV block filter only:icon_scratch:, or switch and then use IR742 for "R" and the "L" for strangely "L":D