Question Detail
Question
To improve the depth of field, a camera lens is 'stopped down' by two f-stops from f/4 to f/8. What adjustment should be made to the shutter speed to maintain the same exposure?
Correct Answer
Option C is the correct answer.
Detailed Explanation
Stopping down from f/4 to f/8 means the aperture area decreases by a factor of (8/4)² = 2² = 4. To maintain the same exposure, the shutter speed (time light enters) must be increased by the same factor, so it should be quadrupled.
Hint
Each f-stop typically corresponds to a factor of two change in light intensity. Moving from f/4 to f/8 is two f-stops, meaning the light collected is reduced by a factor of 4. To compensate, the exposure time must increase by a factor of 4.