M15 is a globular cluster in Pegasus and is one of the most densely packed globulars surrounding the Milky Way. It’s about 33,000 light years away and has over 100,000 stars.
When seen visually through a telescope, globulars can be some of the most spectacular objects in the night sky but photographically they are never quite as eye catching as they are through the eyepiece. This is probably due the limited dynamic range of the camera compared to the human eye. Whatever the reason, few globular images, catch my eye the way nebulae and galaxies do. And, this one is no exception. Though I like the image. It has lots of detail. It just doesn’t pop the way the view can through an eyepiece. All that being said, I’m still pretty happy with it! There is some dust or perhaps IFN on the right hand side of the image. It’s faint and barely visible but I’m pretty sure it’s real and not noise. That’s definitely something you’d never see through an eyepiece!
For all the technical details see astrobin.