Infrared filters and planet photography

[cometcatcher]

I see a few pics around with the Baader IR685nm pass filter. It's a broadband filter that just passes wavelengths longer than 685nm. I have an IR650 and IR720 that I use for landscape photos. Just wondering how they would work? 850nm filters are also available. I have one but it's 55mm and won't fit the optical path.

When combining IR to the other colour channels, is IR substituted for red, added as luminance or what? It can be hard to find out secrets from the masters sometimes. ;)

[multiweb]

I've used a IR720 for deepsky. It mitigates the seeing effects for planets. For DSO it brings up a lot more stars through the dust and nebulosity. Not sure what color it's suppoesed to be but using the palette IR - LIR(50/50) - L seems to do some nice bicolor pics. So IR to red and LUM to blue.

[cometcatcher]

Hi Marc, not planning to do deep sky with it. I took a sub of the Helix nebula with various filters and it disappears at 720nm! These are 1 minute subs for comparison.

[ChrisV]

You just need to spend a few $$s to get a camera and filters that can go to 4 - 8 micrometers. And maybe something to get the camera into space ;).

http://www.spitzer.caltech.edu/images/1531-ssc2006-01a-The-Infrared-Helix

[cometcatcher]

Yeah I saw a few IR photos of the Helix from space and assumed the Earth's atmosphere is blocking a fair bit, cos I'm not getting much at all.

Maybe a "go fund me" plan for an amateur space telescope. ;)

[multiweb]

You still can see a bit of it. I reckon if you do more exposures you'd get an interesting shot.

[cometcatcher]

It also might be bleed through from Ha.