The last thing to add to our effect is a little camera shake to give the explosion some more impact.For this, pre-compose all your layers again so we have a single layer element we can deal with easily
To create the camera shake effect, we will shake the layer itself.
For this, add a slider Expression Control to your layer.If you don't know what expression controls are, you can learn all about these helpful tools in my Adobe After Effects Expression Controls Tutorial
Next, go to the position property of the layer and Alt-Click on the stopwatch icon. This will enable expressions for this property.
In the expression editor type
and then select the pick whip icon and drag it onto the slider effect we added before. This will insert the value of the slider into the expression. Add a closing bracket, a semicolon and click outside of the expression editor. Your expression should now read
wiggle(18, effect("Slider Control")("Slider"));
We have now linked the intensity of the wiggle effect to the value of the slider.Next, animate the value of the slider from 0 to 50 within 2 frames when the explosion starts and then back down to 0 in about 15-20 frames.
This will cause the footage to shake intensely at the moment of explosion and then slowly subside.
The last thing to do is to enable motion blur on the layer and your composition and zoom in a little bit to get rid of any black borders around the layerAnd with that, your explosion VFX is complete!