The Paracorr system dramatically increases the diffraction-limited field of Newtonian & Dobsonian reflector telescopes.
An optical chain is only as good as its weakest link, and the parabolic mirror of reflectors has always limited their performance. Paracorr corrects coma, the image-degrading distortion that makes stars look like blurry comets whose tails point out radially from the center of the field. Previous attempts at coma correction have focused solely on photography rather than observation, or otherwise have been dedicated eyepieces limited to 50° field correction.
This is the Paracorr intended for photography and not observing, and requires your 35mm or digital SLR camera's specific T-mount for use. If you wish to use this device for observing as opposed to photography, you'll need the Paracorr Tunable Top (product number PTT-2002).