Describe how diffraction affects the statement of Question 2. [Hint: See Eq. 24-3 or 25-7.]
Step 1 of 2</p>
The size of the opening of the ‘stop' is specified by the -number (or f-stop) as the f-number can be defined as,
where, the focal length is f and the diameter of the lens opening is D.
Stepping down a lens to a larger f-number indicates a small opening of the lens and the light rays which are coming through the central part of the lens are only accepted.