The small scope fixed on the tube, with low power and a wide field (for example 8×50, about 6°), that helps you aim. Align it with the main telescope in daylight on a distant object. In a straight-through finder the image is upside down.
ToolsInteractive atlas
Related terms
- Red-dot finder
A finder with no magnification that projects a small red dot onto the sky through a window. You place the dot on the target star with both eyes open. Simple and intuitive, it suits beginners well, as long as you keep a spare battery.
- Telrad
A finder with no magnification that projects three red circles of 0.5°, 2° and 4° onto the sky. The circles act as a scale for hopping from a bright star. Many star atlases print these circles to make finding objects easier.
- Star hopping
The method of starting from an easy bright star and hopping from star to star, chart in hand, to the target. A finder or Telrad and the known size of its field help. It is slow at first, but it is how you learn the sky.
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