From: Ray Byrne <ray@in4media.co.uk>

Date: October 1, 2006 11:44:39 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: IR filtering for luminance

Hi Group,

I've a few questions but have broken them down into different posts.

I've spent the last few hours going through the "messages" folder to make sure there isn't THE answers there (touched on but not answered I found)

Post 1.

I'm under the impression that some of the top practitioners of LRGB planetary imaging with mono cameras use IR filters for the Luminance frames. I thought that the reason for this was to narrow down the wave length to Infrared because the turbulence in the atmosphere would be less obvious or may offer longer moments of stillness. I'm using a similar technique with Solar imaging (yet to try it) with a Baader Solar Continuum filter.

In reading an article in Astronomy Now [October 2006 about the Large Binocular Telescope (LBT)] it states that " On a scale of millionths of a metre, which infrared light waves are measured in, the atmosphere is very turbulent...".

Am I wrong in thinking IR for luminance is the way to go and should I just use an unfiltered sequence for luminance?

Also I've read on the group that the other filters (RGB) should have an IR block coating if I'm to not use IR as luminance should the luminance be blocked (ie with an IR blocking filter rather than nothing).

All rather confusing really :op

Ray Byrne