Tech Cues - Aspect ratio / Resolution & Frame rate

Selecting the aspect ratio / resolution and frame rate for your work is a really important part of your planning stage as both of them make a huge technical impact on the film and are often difficult and messey to change once you have begun work.

When taking on commercial work, these are two things you must confirm with the client before production starts and, particulally where your client isn't knowledgeable about these technical aspects, you will need to talk through with them how they plan to use your animation or film work so you can make the most appropriate choices.


Aspect Ratio / Resolution

This is the screen size and shape of your film, the width and height in pixels of each frame.

• The aspect ratio refers to the relationship between the two values eg. 4:3 (4 pixels wide for every 3 pixels high) or 16:9 (16 pixels wide for every 9 pixels high)
• The resolution is the number of pixels on the screen eg. 1920 wide by 1080 tall (giving 2,073,600 pixels per frame).

If your production is going to be projected in a classroom then you will likely need a different set of values to if you are creating a short film to submit to a festival or an advert for a web banner.

Some of the main standard resolution values you will come accross currently:

• 1024 x 768     [4:3]
  This is the old non-widescreen format used on TVs. Many older projectors used in theatres and schools still need this ratio as widescreen footage (16:9) can appear squashed horizontally, or letterboxed to a scale that is harder to see, if used instead.
• 1024 x 576     [16:9]
  Low res wide screen format. Some TV productions are still produced at this resolution but it is rapidly becoming much less common. It's a good size for streaming over the internet to mobile devices or slow connections as it keeps the overall file size down but gives a good picture quality.
• 1280 x 720     [16:9]
  The scale you see with "720p" video, sutable when you need HD footage but also want to keep the file size down. A good size for streaming over the internet if you want a crisper picture and the audience is likely to have a reasonably speedy broadband connection.
• 1920 x 1080     [16:9]
  What is currently reffered to as full HD, aka "1080p" video. Most non-cinema commercial work tends to require this format, and it is the scale you should try to work to for personal productions if you intend to submit them to festivals as it will give a nice, clear picture even when projected onto a cinema screen. Be aware that file sizes can grow very large, very quickly with this resolution so for HD productions you may wish to work at 1280 x 720 resolution on less powerful computers.
• 3996 x 2160     [1.85:1]
  One of the two formats used for American films along with [2.39:1] (see below). The resolution quoted here is for a 4K camera which is a recent introduction and an averadge home computer will not handle projects of 4K resolution. However, the same aspect ratio can be created with a lower resolution such as 1920 x 1038.
• 4096 x 1714     [2.39:1]
  The usuall world cinema standard ratio, also known as "two-four-oh" as it may be thought of as rounded up to 2.40 i.e. [2.4:1] Again I have quoted the ratio for a 4K camera, so for your own productions it would be better to use 1920 x 803.

Frame Rate

As an animator it is important to understand clearly the difference between frame rate and animating on singles, doubles or any other multiple.

The term frame rate should be reserved for when you are talking about your output film and the scene file / timeline you are animating within on the computer. It is the number of frames per second (fps) not the number of drawings per second.

While a 24fps film animated on doubles looks the same as a 12fps film animated on singles, you should not think of animating on doubles as setting up a scene file at 12fps! There are still 24 frames of footage, you only have 12 drawings but you are exposing each drawing twice, hence doubles.

Any change in fps, when also keeping the length of the film the same, will always lead to either frame blending (where you see part of two ajacent frames overlayed on top of each other at the same time) or exposure extension / skipping (where the computer chooses certain frames to show for longer turning singles into doubles etc. when increasing fps or remove entiarly when decreasing fps - very bad if one of your key frames is removed so try to avoid decreasing fps when possible).

When capturing live action footage for a slow motion shot it is always preferable to film at a high frame rate so that you will have a smoother picture once the footage is stretched out to a slower (lower) fps. This does not lead to problems mentioned above, asuming you are using a devision of the original frame rate e.g. 120fps down to 30fps, as the overall length of the footage is also changing.


The main standard fps values you will come accross currently:

• 24fps
  The 'norm' for animation. It divides down into smaller factions very easily: 12, 8, 6, 4, 3, 2, 1. Usually you will want to animate at 24fps even if that means you need to convert it up to a different rate, as getting the timing right will feel more natural. 24 fps is also the European PAL standard frame rate.
• 25fps
  What most basic digital video cameras will film at, also the North American NTFS standard frame rate.
• 30fps
  A more modern frame rate for capturing on digital video cameras.