How to add auto opacity to layers and footage in After Effects [quick video tutorial]

Have you ever worked with tens or hundreds of layers in a project and had difficulties when adding opacity to ALL of them? Have you ever needed a fade expression and didn’t know exactly where to find it, how to look for it, how to write or edit it? Today’s post, by Remus Hossu, provides answers and solutions to all these issues. A video tutorial will take you through all the steps just to make sure that by the end of this blog post you’ll know how to add opacity to layers and footages. First lets take a look at the end result. So here’s our footage layer and as you can see it fades in and out automatically without any keyframes, but what’s cool about it is that if we change the duration of the layer, the fade automatically adjusts to the new length. Very very time-saving. So let’s dive into it. As I mentioned earlier, we won’t use any keyframes but instead we’ll use an expression.

An expression is a small piece of code that affects the properties of a layer.

Now, we have already prepared the fade expression for you, so make sure you download it by clicking on the download now button below.

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So here’s how this works.

1. We’ll choose the layer we want to have the expression applied to and press “t” to bring down the opacity property.
2. Next, we need to hold the “alt” key or “option” on macs and click on the stop watch, next to the  opacity property.
3. Now we just need to copy and paste the expression’s piece of code in the composition panel area. That’s it! You can imagine how useful this trick is when working with tens or maybe hundreds of layers in a single project. Here’s another bonus tip: If you select just the property, in our case the opacity, you can select “Edit” – “Copy expression only”. Then you can just select any layer and hit “ctrl” or “command” + “v” to paste it on the layer. You can also edit the expression, it’s very simple to do: – we have the fade in time, and fade out time indicators, and the numbers represent seconds. So right now it’s set to .5, which means half of a second. – You can play with these numbers as you wish and if you don’t want to fade out the layer, you can set the fadeout value to 0. I hope you enjoyed this quick tip tutorial, stay tuned as we’ll have more coming soon and don’t forget to check out our super cool and easy to use after effects templates. We also have an After Effects Academy where we cover the essentials of After Effects from beginner level to Advanced; we have bonus templates and stock footage, weekly webinars and much much more, so make sure you check that out as well.