What is a red dot finder on a telescope?
Steve says “Trying to locate objects directly through a telescope eyepiece can be quite difficult so it is normal to have a sighting aid installed on the telescope tube and aligned with the main optics.
Historically, this has been a small, low magnification telescope known as a finderscope which gives a wide field of view to allow you to see when you are in the right part of the sky.
However, in recent years, zero magnification finders that project an apparent target or small red dot on the night sky have become very common.
These are known as ‘red dot finders’ and they have the advantages of producing their own illumination and being intuitive to use.”
Email your astronomy queries to Steve at email@example.com and they could get answered in a future issue of BBC Sky at Night Magazine.