Which factor does not affect depth of field?

• A. Shutter speed
• B. Aperture
• C. Focal length
• D. Distance to subject

Answer: (A)

Depth of field describes how much of a scene appears in sharp focus from foreground to background. It is determined by aperture, focal length, and distance to the subject (along with sensor-related circle of confusion). Shutter speed, on the other hand, controls how long the sensor is exposed to light, which affects exposure and motion blur but not the physical range that remains in acceptable focus.

So, you can change shutter speed to brighten or darken an image or to decide whether moving subjects are frozen or blurred, but that won't change how much of the scene is in focus. If you want more or less of the scene sharp from near to far, you adjust aperture, focal length, or how close you are to the subject. For example, using a larger aperture (smaller f-number) makes the background blurrier (shallower DOF), while a smaller aperture (larger f-number) increases overall sharpness across the scene (deeper DOF). A longer focal length also tends to compress perspective and reduce DOF, whereas increasing distance to the subject increases DOF.

Therefore, shutter speed is the factor that does not affect depth of field.