Export the alpha channel in After Effects
Sometimes we need our videos to have transparency information for a project. If you are learning to use Adobe After Effects, you may not know how to include such transparency information in your exports.
This is an important aspect of motion graphics because it is very useful when it comes to representing graphic elements that we can use in other video montages. In fact, with transparency, we can save a lot of work, with a simple drag and drop of files on the video track. So we’re talking about exporting video with an alpha channel to preserve that transparency.
the alpha channel
As you probably already know, video files are made up of red, green, and blue (RGB) channels. But, did you know that there is one more channel? This fourth channel is called the alpha channel. However, only certain video codecs can include an alpha. If you add a sequence to the render queue in After Effects, it will not include an alpha channel by default. This means that the graphics will lack transparency information in the final file. So how do we get such transparency in After Effects?
Transparency and background colors
As we have already mentioned, After Effects does not show the default transparency channel in the control panel by default. Instead, you see the background of the composition. So this is the first change we need to make.
If we want to change the background color we must go to Composition> Composition Settings. To quickly see the transparency, just click the Toggle Transparency button at the bottom of the Composition panel. To see the channels individually we can see it if we press the Show channel button.
Exporting with Transparency
When you export a file from the render queue, After Effects defaults to the composition’s background color. To export with transparency you just have to follow these steps:
Add to render queue
First, you’ll want to add your stream to the render queue. Composition > Add to Render Queue.
Include alpha channel
Then click “Lossless” to bring up the output module settings. Just below “Video Output”, open the channel dropdown menu. Select “RGB + Alpha”, and then click OK. We will specify where we will save the video and finally we will press «Render».
Now we have the video ready to use in any edition Do you want to learn more techniques to make your videos look more professional?