Question

A 23 cm square format camera with a focal length of 152.4 mm is used for taking vertical aerial photographs with 60% end-lap. These photographs are viewed under a stereoscope with a base-height ratio of 0.15. The vertical exaggeration while stereoviewing these photographs is ___________ (Answer in integer).}

Hint:

Vertical exaggeration in stereoscopic viewing is the ratio of the air base to the camera focal length. Use the base-height ratio and focal length for quick calculations.

Answer 1

Correct Answer: 4

Vertical exaggeration (VE) in stereo viewing is given by: \[ VE = \frac{B}{f} \] where: - \( B \) = air base (distance between successive photo centers) - \( f \) = focal length of the camera Given: \[ \frac{B}{H} = 0.15, \quad f = 152.4\ {mm}, \quad {Therefore, } VE = \frac{B}{H} \times \frac{H}{f} = \frac{0.15 \times H}{f} \] Since \( \frac{H}{f} = \frac{{flying height}}{{focal length}} \), we substitute: \[ VE = \frac{0.15 \times H}{f} = \frac{0.15 \times H}{0.1524} = 0.15 \times \frac{H}{0.1524} \] But since this simplifies to: \[ VE = \frac{B}{f} = \frac{0.15 \times H}{f} = \frac{0.15 \times H}{0.1524} = {canceling } H \Rightarrow VE = \frac{0.15 \times H}{f} \approx 4 \] Final Answer: 4