Equipment
极轴校准
Polar alignment
Pointing an equatorial mount at the celestial pole.
A 1° error smears long exposures.
Related terms
- Focal ratio — Focal length divided by aperture; f/5 is faster than f/10.
- Eyepiece — The interchangeable lens that sets magnification.
- Barlow lens — A lens before the eyepiece that doubles the effective focal length.
- Dobsonian — A large reflector on a simple alt-az rocker box.