[cometcatcher (Kevin)]

Originally Posted by traveller

Nice to be able to see behind the bubble. Thanks for sharing Kev.
Bo

Thanks Bo!

Originally Posted by Camelopardalis

That's a great result Kevin

My suspicion - from my own experiments recently - is that the colour cells of the Bayer array can be somewhat transparent outside of the visual spectrum, since the visual spectrum is all a DSLR is designed to care about and they've usually got a UV/IR cut in front of the sensor.

Once it's modded to remove the UV/IR cut, the passband of the colour cells becomes more apparent, and since the pixels of the sensor still have some response to IR wavelengths, when the cut out is removed we end up with photons striking the pixels and we get signal.

From that, I'm guessing the red pixels are responding to Ha + IR, whereas the green and blue just IR. It's possible they could be responding to Ha too, it just depends on where the colour cells start letting photons through again. Does this mean it's "false colour" though

Thanks Dunk. I'm not sure how the camera assigns various wavelengths to certain colour channels in this case. There's not much difference in the blue and green channels but a big difference in the red channel.

Originally Posted by Stevec35

An interesting result for sure. FWIW here's what I got some years back using Astrodon IR filters and the 12.5" RCOS. In case you're wondering these filters produce funny artefacts on bright stars apparently due to reflections from the CCD cover plate according to Don Goldman.

Cheers

Steve

Thanks Steve. Do you remember the wavelength of your IR filter?

Originally Posted by RickS

Certainly a worthwhile experiment, Kevin

Thanks Rick! It was a fun experiment.