BK 909 EQ2 TELESCOPE

Advantages of Refractors:Enclosed optical tube protects optics;Durable and virtually maintenance-free for decades;Don’t require routine collimation;Form high contrast and fine resolution images with no central obstruction;Excellent for lunar, planetary and binary star viewing especially larger apertures;Equatorial mounts allow the telescopes to rotate at the sidereal rate to offset the Earth’s rotation. They consist of two perpendicular axes, one aims to the celestial pole (parallel to the Earth’s axis of rotation) instead of at the horizon, and the other one is perpendicular with it. They are easy to use visually since only the axis that is parallel to the Earth’s axis of rotation needs to be rotated. When properly aligned with the Earth's poles, equatorial mounts can allow the telescope to follow the smooth, arc-like motion of a star across the sky, so they do excellent in taking long exposure photography.