Hi Lee,
Thank you for mentioning the CalculateSkyLimitedExposure tool. - I have not used it before. Below I have collated suggested optimum sub exposure time from various sources. Relevant data was extracted from a 15-minute 3nm Halpha sub collected with QSI 690 in Milton near Brisbane's CBD.
1. PI CalculateSkyLimitedExposure tool: E-readout limit pointed to 80 minutes, while Anstey limit suggested 15-20 minutes.
2. A method from this article (
http://www.hiddenloft.com/notes/SubExposures.pdf)
resulted in a 40-minute optimal exposure time.
3. SGP suggested around 15 minutes.
So anything between 15 minutes up to 80 minutes...wow...
Well, with my reliable yet imperfect mount, with the planes overhead and occasional clouds I think I will stick with what I have been doing so far
