I was asked the question the other day about square pixel format and my motion graphics workflow. Here’s the 4-1-1 on my file format workflow, and why I’ve chosen it. There may be other opinions, but over the past few years (at least in the world of SD), this is my preferred method.

Square Pixel widescreen. When creating a comp in After Effects, I choose the “Square Pixel Widescreen” preset. It gives you a frame size of 864 pixels wide by 486 pixels tall.

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Every computer monitor I use is a square pixel monitor. Video output, however, is not square. For wide screen (16:9), the pixels are actually wider than they are tall. The aspect ratio is 1.2. A computer monitor cannot resolve the non square ratios. When the final image is rendered it looks fine, but when you’re crafting the piece you have to deal with what is referred to as aliasing.

Example of aliasing

[photopress:al.png,thumb,pp_image]

See those jagged edges, especially along the angles of the A? That is aliasing. When rendered and shown on a TV monitor the edges will go away. But when you’re working on it, you have to contend with that visual nastiness.

After Effects does include this little switch (let the arrow direct you) that corrects for the working pixel aspect ratio by squashing everything. See, the aliasing is gone. However our text (in this case) is squished. Now this isn’t a permanent effect, it just makes the aliasing go away while you’re working on the piece. But again the image is distorted, and I just don’t work that way.

[photopress:Picture_2_1_2_3_4_5_6_7_8_9_10_11_12_13_14_15_16_17_18.png,thumb,pp_image]

By beginning the project in square pixel you get the best of both worlds. The lines are not aliased in your working space and you don’t have to work with distorted images.

The second step to my workflow is to render out my video from After Effects. Typically I’ll render either a high quality H.264 or a lossless uncompressed clip. Then I run it through Final Cut Pro. Even if the clip is “as-is” from After Effects I pass it through this step so that every piece I prepare has seen the same workflow.

Upon export from Final Cut I force the square pixel video (864 pixels wide by 486 pixels tall) into a non-square pixel format, which is the preferred format for video systems.

I choose the File > Export As Quicktime option:
[photopress:save.png,thumb,pp_image]

Make sure to use the following settings:
[photopress:settings.png,thumb,pp_image]

Most importantly changing this option to force my square pixel composition into a non-square, video friendly format:
[photopress:pick.png,thumb,pp_image]

That’s it. Render, and done. If you want to read further, this wiki article explains it well.