GREAT DEPTH OF FIELD – WITH THE APERTURE WIDE OPEN?

After learning the relationship between aperture and depth of field, some of my students are confused about my ability to get maximum depth of field in many of my landscape photos, even with the aperture wide open. If a wide aperture creates a shallow depth of field, how is this possible?

To answer the question, it’s important to remember that aperture is only one factor in the depth of field story. Here are the other two:

1. The closer you get to the subject, the shallower the depth of field becomes. And of course it works in reverse: the further you get from the subject, the stronger the DOF will be.
2. The larger the lens you use, the shallower the depth of field becomes; so of course with wide angle lenses the DOF is stronger.

So if you are taking a landscape photo with a wide angle lens, and everything in the view is a good distance (ten metres or more) away from the camera. then the depth of field will naturally be very strong. Virtually everything in your photo will be in focus, regardless of what you do with your aperture. That explains why everything in my Glen Helen Gorge photo is in focus even though it was taken at aperture F-4.

If you plan to have anxiety attacks over depth of field, do it when you are working on close-ups of flowers in the garden. When it comes to wide-angle landscapes, depth of field largely takes care of itself.