Which focal length to use for short film?

[Rick Wise]

Here’s a very brief run-down of focal lengths. First off, they effect field-of-view. As you have discovered, when shooting in a cramped space, you are usually forced to use a wider lens to get a field of view that shows what you need to show.

But that’s just making do, as you’ve noted. The main characteristics of wide lenses is that they “push back” what’s in the background, while long lenses compress background and foreground. So if you want something to rush to the camera, usually a wide lens will work best. Let’s say you have your hero walking toward the lens and you are shooting him from a good distance with a very long lens: he/she will stay relatively the same size in the frame for a very long time, only gradually taking up more and more of the frame. Now replace that long lens with a wide one, and your hero will start tiny in the frame and rapidly grow in size. So the kinetics of movement are much more dynamic when the person/object is moving toward the camera with a wide lens.

But if the camera is stationary and you are panning r-l or l-r, a long lens is likely going to give you a stronger sens of motion as you pan with your actor(s) or objects.

If you add camera movement (dolly, steadicam, or the like) in general wide lenses give you more dynamic kinetics, as well as forced perspective. Go back and look at the use of wide lenses in Citizen Kane for a graphic demonstration.

Moving the lens is much harder with long lenses, as any vibration/jiggle jumps out at the viewer. To hand-hold a camera following someone you will have far more success shooting with a wide lens close to the subject than a long lens far from the subject. Close and wide enough, and the person’s own movements will mask your own.

There is also that other issue: focus, or depth of field. At a given distance, and a given f/stop, a wide lens has a much deeper depth of field than a long one. But you cannot gain depth of field by going to a wider lens unless you accept a wider field of view. The reason: when you switch to a wider lens and keep the same field of view, you have to move the camera much closer, and at this new close position you end up with the same depth of field you had originally. (The closer the lens is to the subject, the more shallow the depth of field.) The only way to increase depth of field is to add light or bump up ISO sensitivity or open the shutter or slow down the recording speed: any of those will allow you to close the iris more, thereby increasing depth of field. Closing the iris 2 stops doubles the depth of field.

Finally, a note about recording size: The larger the recording size, whether film or video, the longer the lens you need for the same field of view. A “normal” lens shooting 16mm film is a 25mm. A “normal” lens shooting 35mm film is a 50mm. So with large chips/film-sizes you are bound to use a longer lens. That effects compression of background. That effects depth of field. That “filmic” look of 35mm features comes in part from the use of relatively long lenses by comparison to video cameras — until recently. We now have DSLRs and pro video cameras with large sensors, and so can naturally gravitate to longer lenses to isolate subjects with shallow depth of field, if we want to. Equally, when we go to a relatively wide lens, we can get the dramatic kinetics and forced perspective those lenses produce. With large sensors, our potential arsenal of looks is greatly increased.

As to your specific question about those two directors, I’d have to screen some of their work afresh to answer your question. Maybe you can answer your own questions with the guidelines above. Hope so.

Rick Wise
Cinematographer
San Francisco Bay Area
https://www.RickWiseDP.com

[Jon Gianelli]

What a huge help. Thank you. I really want to go from this being a craft for me to more of an art. I’ve done plenty of commercial videos, weddings, events, etc. but I don’t feel like I’m there yet when it comes to the look and feel of a scripted production.