Coma Corrector for Newton Ø 50.8 mm (2")

In brief

• Designed for any reflector in the f/3.5 - f/6 range
• Eliminates the inherent coma in the optical design of the reflector and provides sharp stars across the entire field of view.
• Also usable for visual work with an eyepiece.
• Depending on the camera or eyepiece, different optional extension rings will be necessary to achieve the correct spacing for optimal coma correction.
• Fully multi-coated optics

Master the coma and enjoy images with sharp stars across the entire field of view or the photographic image format of your fast Newtonian reflector with the Photo-Visual Coma Corrector Ø 50.8 mm (2").

The Photo-Visual Coma Corrector Ø 50.8 mm (2") for Newton minimizes the inherent coma of fast Newtonian reflectors with focal ratios of f/3.5 to f/6. Coma appears as comet-shaped, distorted stars and progressively worsens as you move away from the center of the field. This coma corrector significantly reduces this effect as well as the effects of field curvature, making stars sharp across the entire field of view or image frame. The Photo-Visual Coma Corrector works equally well for astrophotography and visual observation through the eyepiece.

Design

The optics are integrated into a device with a diameter of Ø 50.8 mm (2"), which screws into the upper housing, which features an eyepiece holder for Ø 50.8 mm (2") eyepieces. The eyepiece holder is equipped with a non-marring brass compression ring and two thumbscrews. The bottom of the eyepiece is threaded for Ø 50.8 mm (2") filters. The third component is an M48-T2 (M42) adapter ring, useful when the coma corrector is used for astrophotography.

Visual use

For visual use, additional spacing may be necessary for certain eyepieces. Some users report that adding a 19 mm spacing between the upper housing and the optical nose allows for perfect focus with their wide-field eyepieces.

The Photo-Visual Coma Corrector provides a magnification factor of 1.1x. The optics are fully multi-coated for maximum light transmission.

Astrophotographic

For astrophotographic use, you need to unscrew and set aside the upper housing and only use the optical compartment that contains the device. The rear focal point of the coma corrector is approximately 75 mm. For use on digital SLR cameras, you will need a 20 mm spacer (sold separately) to achieve correct image focus. For astronomical cameras, additional spacing will be necessary, the amount of which can be determined by considering the position of your camera's sensor relative to its front plate.