Question

The Instantaneous FOV (Field Of Vision) changes with the position of view.

(a) True

(b) False

This question was posed to me in an international level competition.

My question comes from Head Up Displays in section Displays and Man-Machine Interaction of Avionics

Answer 1

Correct answer is (a) True

Easiest explanation: The instantaneous FOV is the total angular coverage of the outside world scene which can be viewed by the pilot at any particular instant.

IFOV=2tan^-1 D/2L, where a D= diameter of collimating lens and L=length of pilot’s eyes to the collimating lens. Clearly, as the position of view changes, L changes resulting in a change in IFOV.