ES 2" HR Coma Corrector for photography and observing with newtonians

The HR Coma Corrector from Explore Scientific is optimised for observing and for astrophotography through fast Newtonian telescopes.

The coma corrector extends the focal length of the telescope only by 6% and works with all Newtonian telescopes f/3 or slower. The focus position has to be at least 32 mm above the 2" receptacle. This applies to almost all commercially available Newtonian telescopes. With 85 mm length, the corrector is still relatively short, it does not extend into the tube.

Astrophotography with the Explore Scientific HR Coma Corrector:

The corrector is delivered with photographic adapters (T2 and M48x0,75). Theys are screwed on instead of of the helical fokuser. The working distance is standard - 55 mm from the thread for easy adaption of CCD and DSLR cameras. The fully illuminated and corrected field has 30 mm diameter, so it is also suitable for medium-sized sensors up to APS-C format.

Image at left: Chuck Kimball using f/3.9 Carbon PhotoNewton with DSLR - APS-C sensor.

Observing with the Explore Scientific HR Coma Corrector:

The corrector comes with a 2" helical focuser. Attach the eyepiece to the coma corrector and you will see finest details on planets, from corner to corner. The Cassini division is visible as soon as Saturn comes into view, rather than only in the central area. Stars are tack-sharp even at the edge of the field in the eyepiece. This is made possible by s visual polychromatic Strehl ratio of 0.98 at f/4 and still of 0.96 at f/3! Therefore the corrector can always remain attached to the telescope.