Equipment
热平衡
Cool-down
A scope reaching ambient temperature.
Big mirrors need 30–60 minutes or the image boils.
Related terms
- Aperture — The diameter of the objective — it sets light grasp and resolution.
- 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.