the best mirror lens for 35mm, Vivitar Series 1 800mm f8. Manufactured by Perkin Elmer (professional astro optics company). Extremely high build quality, can put any T-ring (Canon, Nikon, et al) on it. Currently, has Nikon T-ring. Comes with heavy-duty case & 4 colored filters.
perfect lens for solar eclipses: 2 sun-diameters of corona on each side, along diagonal. Very compact, perfect for travel.
rare, out of production. Beats out Nikon or Canon mirror lenses. excellent conditon, never used by me. asking $800, obo.