I am sure the work of Nick Risinger has been a topic of discussion before on the forums but I would like to pose a question. Attached is a photograph of Risingers imaging setup...which includes six FLI ML-8300 monochrome cameras..one each to capture LRGB & Ha...but what data is the sixth camera capturing??
For those whom haven't heard of Nick Risinger or his work..check out his website.
http://skysurvey.org/