Use Imaging Camera in Eyepiece Holder 1″ Male C-Mount Threads Standard 1.25″ Nosepiece Accepts Mounted and Unmounted Filters Use the Alpine Astronomical Baader 1″ C-Mount Adapter with 1.25″ Nosepiece to quickly and easily mount your CCD imaging camera into a standard eyepiece holder or other accessory, like a diagonal or Barlow lens. The nosepiece is threaded to accept standard 1.25″ astronomical filters and a retention ring is also included to permanently install unmounted filters from 27.5 to 28mm in diameter. Unmounted filters such as light pollution, IR-cut, and haze filters will dramatically improve image quality and can be installed deep into the 18mm nosepiece, with mounted specialty filters such as neutral density, colored planetary, or nebulae filters simply screwed into the front of the nosepiece.