Find the f-number of a telescope with an objective diameter of 8.0 cm and a focal length of 95 cm.
Find the aperture diameter of an f/1.5 all-sky meteor camera lens with a focal length of 2.0 mm.
1)The f-number(f/stop) of an optical system is the ratio of the system's focal length to the diameter of the entrance pupil. It is a dimensionless number that is a quantitative measure of lens speed. It is always represented as f/number.
f/number =Focal Length of the Telescope/ Objective(Aperture) Diameter
The answer for f/number is f/11.875
2) Using the same formula from above
Aperture Diameter = Focal Length of the Camera Lens / (f/number) Note- f/number is a single term
Therefore the Aperture Diameter is 1.333 mm.
We should know that objective diameter and the aperture diameter are the one and same things
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