This was one of my first deep-sky targets, and I was hopelessly naïve. I couldn’t understand why the cluster, which appeared as incredibly bright and densely packed in other photos, looked so dim and sparse in my early attempts, even after stacking many, relatively long exposures. At first, I thought that I’d aimed the telescope at the wrong globular star cluster, perhaps the nearby, dimmer M92 cluster. I eventually learned from helpful videos that multiple applications of PhotoShop adjustment layers or Pixinsight transformations could enhance the brilliance and draw out the dense structure of the globular cluster. And as an added bonus in this instance, such adjustments can also reveal two distant galaxies: NGC 6207 (in the lower left-hand corner), and PGC 2085007 (about halfway back to the cluster). NGC 6207 is 50 million light-years away; PGC 2085007, half a billion light-years away.
Telescope: Stellarvue SVR-90 Raptor with 0.8 focal reducer (f/5.6, focal length 504 mm)
Mount: StarWatcher HEQ5.
Imaging Camera: ZWO ASI294 MC Pro
Filter: Optolong 2” L-Pro
Controller: ASIAIR Plus
Software: Deep Sky Stacker, PixInsight, PhotoShop
Dates: Jun to Sept 2021; Oct 2022; and Sept 2023.