Back at the beginning of March I took a couple of hours worth of 10 minute exposures of the Leo Triplet (M65, M66 & NGC3628). Having stacked them in Maxim as I normally do I found that the intensities were very wrong when opening the fits file in Pixinsight for further processing. I haven’t got to the bottom of this yet but I’ve re-calibrated and stacked using Pixinsight instead which has worked around the problem.
Looking back through my images I first took pictures of this group at Kelling back in spring 2010 .