focuser
focuser · focusers
A device which allows one to adjust the focus of an instrument such as a telescopeA device which allows one to adjust the focus of an instrument such as a telescope.
Dictionary text adapted from Wiktionary (Wiktionary contributors, CC BY-SA 4.0) and Open English WordNet / Princeton WordNet (CC BY 4.0, WordNet License); shared under CC BY-SA 4.0. Example sentences and recordings are credited where they appear.