I was playing around with a IR pass filter some weeks back, but only just remembered i took a image to see how it would look.
It actually came out OK. You can see just which stars have huge luminance compared to visible light. In the core of M42 can be seen somebright stars, but you actually see more stars in IR, plus a bright star just to the right of M42 that just isnt there on the other..
One thing i noticed, jet black background !.
jeepers, no skyglow with this sucker in there.
G'day Theo, Can you please give details of the capture device and filter is it a 1 1/4", also aperture of scope? The IR image is interesting and somewhat surprising. It must be too early in the morning for me but I don't quite understand how there would be white stars in an IR only Image. I would expect every thing to be deep red, or if grayscaled/monochrome; black and white?
I used a 49mm filter with a 200mm telephoto lens.
Color is actually pretty close.
Also IR will fill the wells of the pixels without a problem as it just passes thru the debayer filter. IR is a shorter wavelength and the debayer filter hasnt got a IR block, thus the pixel wells collect the same amount of light/photons.
This is why filters have a IR block and a UV block, to prevent this problem.
When i did the debayer color conversion, i just left it as it was. There was no need to get the exact balance correct. It doesnt make any difference to the eye. I could have made it more red if i wanted, but its more easily seen as is.
G'day Theo, Yes I see now that you point it out . I was forgetting the bayer filters. Colour is ok anyway.......it looks good, and as Mike said very interesting result*
(edit) Mike didn't say it I just think it.
Tnx,
Doug
. I was forgetting the bayer filters. Colour is ok anyway.......it looks good, and as Mike said very interesting result*
