Fig.6 - Saturn & Jupiter with its four largest moons through an 8-inch f/5 Teleskop-Service ONTC Newtonian reflector on an equatorial
platform on December 17, 2020. Nikon D7500 (h-alpha modified camera), 1/15 s at ISO 400. A TeleVue 2x Powermate barlow lens was used, leading to an
effective aperture of f/10 and a total focal length of 2000 mm.