An ideal visual and photographic tool for fast Dobsonian optical tube assemblies (OTAs), the Alpine Astronomical Baader 2" Mark III Multi-Purpose Coma Corrector (MPCC) improves your views and image quality on any OTA with a removable 2" collar. It eliminates distracting off-axis comas and ensures stars remain tack sharp all the way to the edges—without adding any magnification, reducing the focal length, or narrowing the field of view.