Definition of effective aperture
: the diameter of the entrance pupil of an optical system; specifically : the apparent diameter of the diaphragm opening in a camera lens as seen through the front of the lens
Start your free trial today and get unlimited access to America's largest dictionary, with:
- More than 250,000 words that aren't in our free dictionary
- Expanded definitions, etymologies, and usage notes
- Advanced search features
- Ad free!
Seen and Heard
What made you want to look up effective aperture? Please tell us where you read or heard it (including the quote, if possible).