Sky Quality Meters › Forums › Imaging › SQL › Sky Quality Meters 15 September 2015 at 9:48 pm #577039 Hazel McGeeParticipant Hi Nick There was a good article on the subject by John Prockter in the 2012 June Journal: https://britastro.org/journal_old/pdf/122-3prockter.pdf Cheers Hazel McGee