A geometry calculator, not a fitted bee odometer. A point feature sits beside a straight path. We calculate its instantaneous angular speed when the observer passes closest to it.
At closest passage, angular speed = forward speed ÷ perpendicular distance, in radians per second. Multiply by 180/π for degrees per second. The model omits eye movements, flight height, contrast, texture, integration over a whole route and neural processing.
Start at 1 m/s. A feature 1 m away moves at 57.30 degrees/s at closest passage; a feature 10 m away moves at 5.73 degrees/s. Double speed, then double both distances. Compare what changes.