a set of telescopes.

telescope astronomy optics lens mirror space starlight aperture magnification refractor reflector eyepiece tripod observatory focus light nebula galaxy planet star moon saturn jupiter mars venus sky constellation astrophotography night horizon parallax objective barlow collimation solar eclipse sidereal zenith altitude azimuth equatorial mount finder scope field diameter prism magnify resolution clarity distance alignment polar diffraction spectrum viewing observation rings ringsystem cluster comet meteor atmosphere telescopes dark blue elements universe