I am using Adobe After Effects CC 2017. What is the composition settings I should use to make YouTube videos?
I am also using After Effects on an iMac.
Thanks for your help.
The standard is still HD, 1920 X 1080 and 29.97 fps for the US and most of the world or 25 fps for Europe and PAL countries. Some folks like 24 or 23.976. Make sure you use one of the HDTV presets for your composition settings.
Now let's talk rendering. You have two choices. You can send your AE composition to the Adobe Media Encoder - which is the best option unless you are using some effects or the C4D renderer to extrude 3D layers. When the AME opens up pick h.254 and then choose the YouTube Preset that matches your frame rate and frame size. Do NOT create custom settings until you have spend at least a few hours learning about video formats and compression settings. You'll just foul things up.
The second option, which you should use for complicated compositions that are using GPU accelerated effects, is to use the Lossless preset in the Output Module of the Render Cue to render a digital intermediate. This file is not intended for playback or distribution. It will be very large because it is a lossless format. Then you load your lossless file into the Adobe Media Encoder and render your deliverable h.264 mp4 using the appropriate YouTube preset.
Until you have expert knowledge on video standards, frame rates, formats and compression you should not ever see the word custom in composition settings or in the Output Module or Adobe Media Encoder. The standard presets will produce high quality work suitable for professional production. One wrong move on a custom setting can completely foul up things and give you problems that are difficult if not impossible to solve without starting over.