Which factors can lead to a greater depth of field in photography?

• A. Using a telephoto lens, wide aperture, and fast shutter
• B. Using a wide angle lens with a high f-stop and auto iris
• C. Using a macro lens at close focusing distance
• D. Using digital zoom only

Answer: (B)

Depth of field is the range in a photo that appears sharp from foreground to background. It grows when you use a shorter focal length (a wide-angle lens) and when you stop the lens down to a higher f-number (a smaller aperture). The combination of a wide-angle lens with a high f-stop moves more of the scene into focus, especially when you’re not focusing very close to the subject. The auto iris simply helps keep exposure correct when you choose that small aperture, but the true factor increasing depth of field is the small aperture paired with the wide-angle perspective.

The other scenarios don’t promote greater depth of field: a telephoto lens tends to reduce depth of field even if light exposure is managed; macro lenses at close focusing distances produce very shallow depth of field; digital zoom doesn’t change the physics of focus and field depth.