Quote:
Originally Posted by Merlin66
Sil,
A double stacked SM40 will effectively filter the solar light to a very narrow 0.4A bandwidth centred on Ha. No other light get through.
The RGB camera response will depend very much on the overlap of the Bayer Matrix filters within the camera. There's no easy way of adding additional filters to isolate the Ha wavelength.
Summary: Although the incoming light is 100% monochromatic (red, Ha) there may be a response recorded on the R and G pixels due to the Bayer filters. These should be ignored. Just work with the red channel.
Hope this helps.
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Hello M,
Yes there is indeed an extended response, surprisingly well past what would normally be considered blue or green and deep in to the red. In fact all the way up to Ha at 656nm with a
QE of ~8% in the GREEN Channel,
QE of ~6% in the BLUE Channel
compared with an obviously higher
QE of ~52% in the RED Channel.
Data is read from ASO120 Colour QE graph attached below, from webpage:
https://astronomy-imaging-camera.com...si120mc-color/.
Even though the QE is not huge in the blue and green, it would be a shame to discard it, without at least a look see, especially as it would already be ultra-narrow band filtered by the solarscope. It would be worth a try perhaps with some scaling of the various intensities to counteract/perhaps to try to equalise the differing QE between channels (try, but watch noise in so amplifying/doing), and then put in to monochrome for final result.
Best
JA