At 24 FPS with a shutter angle of 180 degrees, what is the effective exposure time per frame?

At 24 FPS with a shutter angle of 180 degrees, what is the effective exposure time per frame?

• A. 1/24 second
• B. 1/48 second
• C. 1/96 second
• D. 1/12 second

Answer: (B)

Exposure per frame is driven by the shutter angle: the shutter is open for a fraction of the frame time equal to (shutter angle/360). At 24 frames per second, each frame lasts 1/24 second. With a 180° shutter, the shutter is open for half of that frame time, giving (180/360) × (1/24) = 1/48 second. That’s why the effective exposure per frame is 1/48 second. For context, a full 360° shutter would expose for the full 1/24 s, and a 90° shutter would expose for 1/96 s.

Exposure per frame is driven by the shutter angle: the shutter is open for a fraction of the frame time equal to (shutter angle/360). At 24 frames per second, each frame lasts 1/24 second. With a 180° shutter, the shutter is open for half of that frame time, giving (180/360) × (1/24) = 1/48 second. That’s why the effective exposure per frame is 1/48 second. For context, a full 360° shutter would expose for the full 1/24 s, and a 90° shutter would expose for 1/96 s.