Working with Depth of Field and Hyperfocal point
I’ve been reading John and Barbara Gerlach’s fantastic new book Digital Landscape Photography and attempting to gain a full understanding of these key landscape photography concepts: Depth of Field (DoF), Hyperfocal Distance and Circle of Confusion (CoC). Below is a photo I shot with several different combinations of settings to see how and if the old “focus 1/3 of the distance into the scene” works. Well, it seems it works some of the time. Below is a cropped version of an image I took at 200m, f16 with a full frame 5D — the key variables that determine DoF and Hyperfocal distance. In the photo below I focused on the wagon, about 1/3 of the way into the scene by me rough “eye” to see how far into infinity sharpness would extend to test the rule. Needless to say, from the lack of sharpness of the leaves in the background, the 1/3 rule does not work for long focal lengths where DoF is relatively shallow – even at f16. So, I’ve more to learn and tomorrow I’m out to try shorter focal lengths with different aperatures.
To calculate these variables, I use a handy Apple application for the iPhone called “PhotoCalc.” It’s great for doing a quick check of hyperfocal distance given the focal length, aperture and distance to the focal point (subject) used. John and Barbara Gerlach recommend a great web site where calculators for DoF and hyperfocal distance can be found, as well: cambridgeincolour.com/tutorials/hyperfocal-distance.htm. There are links to other great calculators and explanations of sometimes confusing concepts like Circle of Confusion.
