STOP NUMBER as NOUN

1. Meaning
   • the ratio of the focal length to the diameter of a (camera) lens system
   Synonym(s)
   • focal ratio (what does focal ratio mean?)
   • f number (what does f number mean?)
   • speed (what does speed mean?)
   Hypernyms(s) stop number is a kind of… Example: animal is a hypernym of mammal, plant is a hypernym of flower
   • ratio (what does ratio mean?)