|equivalent focal length|
|optics the ratio of the size of an image of a small distant object near the optical axis to the angular distance of the object in radians|
|an extraordinary or unusual thing, person, or event; an exceptional example or instance.|
|a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.|
Dictionary.com presents 366 FAQs, incorporating some of the frequently asked questions from the past with newer queries.