Setting circles are used on telescopes equipped with an equatorial mount to find astronomical objects in the sky by their equatorial coordinates often used in star charts or ephemeris.

• 定位圈 是设置在望远镜的赤道仪式架台上的装置，这是与星图或星历表上常用的赤道座标一样的天球座标系统，可以协助寻找在天空中的目标天体。