Today’s Question: I was on a photo workshop with an emphasis on landscape photography, and there was a lot of talk about focusing one-third of the way into the frame for maximum depth of field. Is there any truth to this notion, and if so, why?
Tim’s Quick Answer: The advice you’re referring to is based on a reasonable rule of thumb relating to the concept of hyperfocal distance for maximizing depth of field. However, it isn’t universally true that focusing a third of the way into the frame will maximize depth of field.
More Detail: Hyperfocal distance is the closest distance you can focus while still having the depth of field extend all the way to infinity. This principal can therefore be helpful when you want to achieve maximum depth of field, which is a common goal in landscape photography.
However, what is most important is that the hyperfocal distance is beyond the distance at which you’ll be focusing. Otherwise, you won’t have depth of field that extends all the way to infinity.
For example, let’s assume the use of a 50mm lens that can stop down to a minimum aperture size of f/22. The hyperfocal distance for this configuration is about 20 feet. So, if the intent is to set the focus on an object that is ten feet away, you won’t have depth of field that extends all the way to infinity. In fact, the depth of field in this sample scenario would only be about 14 feet.
If, on the other hand, you were focusing at 20 feet then you would have depth of field that extends all the way to infinity, with a total depth of field that extends from about 9 feet to infinity.
Because of situations like this, I don’t recommend always focusing one-third of the way into the frame, or one-third of the way to the key subject. Instead, when maximizing depth of field is important, and especially when you have a subject relatively close to the camera that you want to have in focus, it is important to calculate depth of field to confirm what is possible with your intended lens and camera settings.
You can learn about calculating depth of field in the context of hyperfocal distance in Chapter 2, Lessons 5, 6, and 7, in my “Photo Planning with PhotoPills” video course, which you can find here:
https://www.greylearning.com/courses/photopills
