Wednesday, February 9, 2011

Cinematography Basics: Zoom and Enhance

Tomorrow I'll have a post up about Unity, but let's get some other camera techniques out of the way: zoom and focus. Both of these also contribute to framing, which will be one of the main challenges that I'll have to handle with my intelligent cameras.

Zooming involves adjusting the focal length of the camera. It's probably not something that I'll be dealing with a lot, since my cameras can just move forwards and backwards in space if necessary. There is one cool thing that zooms can be used for, though it's not really a high-priority for me to implement: the so-called "Vertigo Shot," which you may know from Hitchcock's "Vertigo" (or maybe "Jaws"). The idea is to move the camera forward while zooming out, or move the camera backward while zooming in. That way, it makes it seem the distance between the foreground and background is shrinking or stretching. Here's a video with some examples of it used in famous movies:


Focus has to do with the camera's depth of field. I think it would be cool to play around with this: establishing shots should probably have a deep focus so everything is clear; once the camera moves in tighter, objects tied to the event can be kept in focus, while the background can be blurrier. There's also a technique called "rack-focus," where the focus shifts between multiple planes. If there's ever a time where a camera is framing one event, and a second event occurs within the frame but in the background, a rack-focus could be used to direct the audience's attention.


So now we've talking about getting things into the frame. But once they're in there, composition is important too! Here are a few rules:

Don't cut off people at the ankles, knees, or neck. It just looks odd. Still, it will be difficult to tell if objects are characters, so it will be tough for the cameras to avoid cutting people off... to avoid this, my cameras will probably always start with establishing shots, and then make sure to to keep a large chunk of the object in frame when doing closer shots. If only a small part of the object is in frame (like in the "bad" example below) things look weird.



Let the actor lead. If a camera is following a character, it should wait for the character to start walking before it begins panning. If the camera moves prematurely, it can be jarring and pull you out of the movie, because it's obvious that the cameraman started moving in anticipation of what he knew would happen next. This shouldn't be a problem for my project, because the cameras don't know what's going to happen next anyway, and are always waiting for their targets to make the first move. I've sometimes heard that if the camera and character are both moving, the camera should stop before the character does… But I don't think this is as glaring as the start of the action. Besides, my cameras wouldn't know to stop early anyway.



Use negative space. Framing things in the dead-center of the composition is boring. But this is especially important with movement: if a character is walking and the camera is tracking next to them, the composition should leave empty space in from of the character. You really don't want the character to look like they're walking off the frame, or for it to seem like the camera isn't keeping up. Even when a character is still, the camera should leave space in the direction that they're looking. If this rule is being broken, there's probably a reason for it…



…Like maybe you're watching a horror movie. Once you know to look out for this, you can ready yourself for lots of cheap jump scares.

Sure, it's usually just a cat jumping out. But at least you know that the cameraman was shooting that way on purpose.

Next time on Cinematography Basics: Editing and cuts!

2 comments:

  1. In all seriousness - is that how they do those vertigo shots? I was having a discussion with someone recently (I forget which film did it), but where they condensed the viewing volume like that... and I could never figure out how that was actually done. Is that still how it's done?

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  2. It sure is!

    Wikipedia has more technical stuff about it at http://en.wikipedia.org/wiki/Vertigo_shot

    And if you feel like procrastinating on TV Tropes, they have a ton of examples at http://tvtropes.org/pmwiki/pmwiki.php/Main/VertigoEffect

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