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I'd like to add another dimension of 'respecting the light', for discussion. Light intensity is one issue, colour is another (particularly when imaging with narrow-band filters).
Nebulae, for instance, emit light in narrow bands. The Tarantula Nebula emits most strongly at the OIII (501nm) band, followed by a much weaker Ha (656nm), then progressively weaker emissions at Hb (486nm) and Hy (434nm). The Orion Nebula emits most strongly overall in Ha but the inner part also emits strongly in OIII (less strength further out). Weaker emissions are Hb, HeI (585nm) and Hy in that order. These are generalisations of course.
If you're imaging with narrowband filters how do you respect all the (visible) light coming from a nebula? Is it 'respectful' to hit the Tarantula Nebula hard with an Ha narrow-band filter? Or just with an OIII filter for that matter? How do you approach such imaging?
Cheers -
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