TeleVue Paracorr Coma Corrector

TeleVue Paracorr is a universal coma corrector that tightens and intensifies star images on all fast focal ratio Newtonian telescopes. Coma is an inherent property of telescopes using parabolic mirrors. Light from a point source in the center of the field, such as a star, is perfectly focused at the focal point of the mirror. Light from a point source that is off-center will not reach focus at the same point. The further off-axis the source, the worse this effect is. In fast Newtonian systems Coma makes stars look like blurry comets whose tails point out radially from the center of the field. All parabolic mirrors used in Newtonian reflecting telescopes are limited in field sharpness due to coma. Even a perfectly made 13" f/4.5 parabola has only about 0.1 degree diffraction limited field. Previous attempts to correct for coma have been limited in usefulness. Some correctors were designed mainly for astrophotography. Dedicated coma correcting eyepieces were another approach. However, these were limited to 50 degree apparent fields and would orphan your existing eyepiece collection.

The TeleVue Paracorr is a universal corrector that tightens and intensifies star images [see performance graphs here] on all f-ratios from f/3.5 to f/8 without adding any false color or spherical aberration! You no longer have to constantly shift a Dobsonian to keep objects centered for sharp viewing. Using a TeleVue eyepiece, put M-13 at the edge of the field and enjoy resolving its beauty as it drifts across your view. Paracorr is recommended for use with all TeleVue eyepieces because our Plössls, Radians, Panoptics, and Naglers achieve higher levels of aberration correction than competitive models. However, Paracorr is also compatible with other eyepiece makes.