Hello!
The first filter that I purchased for my Infinity color was a 2" Baader IR/UV cut filter. It does seem to minimize star bloating or "blooming" when imagining with longer exposure times. It's a good general purpose filter for deep sky but you will find many other types in your research. I'm now looking to add "narrowband" filters including H alfa and O III units that will only allow certain wavelengths of light to pass to your cameras sensor. These filters can really highlight some of your target subjects and minimize what you don't want in your image. Choosing which one to use will depend upon your target DSO that may be a reflection or emission nebula (or both), etc. Hope that helps a little and enjoy your research!
Craig