Ideal for visual observation as well as prime focus, eyepiece projection, and afocal imaging astrophotography techniques, the Vixen Optics SD81S 81mm f/8 ED APO Refractor Telescope is an ideal addition to an amateur astronomer or photographer's kit.
Optically, Vixen outfitted the SD81S with FPL53 extra-low dispersion (ED) glass, in a fully multi-coated apochromatic lens system that corrects for both spherical and chromatic aberrations, astigmatism, and off-axis comas. This correction creates a wide flat field of view without distortion and removes the blue-tinted "halo" effect for true high-contrast color transmission
Aperture 81mm
Focal Length 625mm
Focal Ratio f/7.7
