Recently bought PixInsight so I have just been digging up some old images that I took a year or two ago from when I was studying the period of RR Lyrae Variables within a few globular clusters.
I cannot quite remember what I did but I am pretty sure it is 150 odd 10 sec subs with my D700, taken as RAW Monochrome through Maxim DL.
Great cluster but you are missing the star colour. If you want colour in your image, after calibration And registration you need to debayer the subs using the debayer process. You should be able to get a range of star colours even if you have selected the RAW monochrome setting in Maxim.
