Watch: 71 Uses of the Split Diopter Shot—in One Movie

Behold the beauty of the split diopter.

Though its name may not slide off the tongue, the split diopter shot is one you've seen in many films (especially Brian De Palma's) and will see in many more. Simply put, the shot uses a mechanism which contains a convex lens; the curved nature of the lens puts objects in the foreground and background into equal focus.

There's a lot that can be done with this shot. Most benignly, you might show a moment of irony. For example, a policeman eats a donut, smiling a little as he does so. Across the street, seen as clearly as we see the policeman, three robbers dressed as American presidents leave a bank, carrying large bags, presumably full of money. The shot could also be used to build tension or induce panic. Who hasn't jumped with alarm during a horror film to see a hero, drenched with sweat, looking all around for the zombie he or she is certain is not far away, as that very zombie approaches the hero from behind?

Vashi Nedomansky's video essay on The Andromeda Strain is a highly detailed, focused study of the film's use of the split diopter shot to build and hold tension in a film. 

Director Robert Wise and DP Richard H. Kline apparently used 206 such shots in this pioneer of the "a scary disease is here, and it's out of control" film; Nedomansky has chosen 71 of his favorites for this piece. Though the shots themselves may not necessarily exude tension or suspense, it's easy enough to see that the technique was being used to create an atmosphere. What better shot for a movie about an uncontrollable spreading physical malady than a shot which encourages such intense vigilance?

For more, here's how to use split diopters to achieve deep depth of field    

Your Comment


Interesting Post. Thank you.

August 26, 2016 at 12:09PM, Edited August 26, 12:09PM

Arun Meegada
Moviemaker in the Making

One of my favorite films. Fantastic sets and hard light. Beautiful

August 27, 2016 at 7:50AM

Richard Krall

Most (not all) of those shots could have been accomplished with higher apertures with today's more light sensitive cameras.

August 27, 2016 at 8:24AM


A high aperture will not give you the out-of-focus areas. If you want to create shallow focus with existing footage, you can create a depth map of your shot in Photoshop, import that map into After Effects, and then use a blur filter to designate out of focus areas. You will likely need to create a mask around the actors. I used this effect to improve the look of a shot when the background was too static. Worth Googling how to do.

August 27, 2016 at 10:02AM

David Barrington

I don't think anyone wrote seriously about this film when it debuted, but it seems obvious now that each of these setups (and likely all the others) were intended to mimic comic books, in which everything is always "in focus," no matter where it appears in the composition.

September 1, 2016 at 8:50PM, Edited September 1, 8:50PM

Bob Byars

Great Post.

April 13, 2018 at 12:59AM, Edited April 13, 12:59AM

Justine Marie
i love Indian food