astrobarn

On 04/12/2023 at 11:15, BrendanC said:

I've been thinking a lot about filters recently, and whereas everyone says it makes sense having one filter doing Ha and O3 and another doing S2 and O3, I just don't see the logic. Surely, if you combine the data from these two filters, you're going to get twice the amount of O3 than Ha or S2? And in fact given that the bayer matrix has twice as many green pixels, this would actually result in four times O3? Am I missing something? 

OIII is a lot fainter than HA and SII, so having more photons for OIII will result in a more balanced image. No one is out there doing exactly equivalent exposures for OII, HA and SII. HA is by far the most abundant spectra in *most* emission nebulae.