Hello sir.

Really glad you are following the course.
So there are a couple of ways to add motion blur but adding it to the null object will not work.

You actually need to add it to the layers one by one.

Based on the method I taught you, there is actually another way to do this but it will slow down your work a mile cause it’s not the most friendly effect for systems.

You can animate all the layers you need, precompose them and say call it ‘COMP 1’
then in your comp 1, add an adjustment layer at the top of all the layers animated then add an effect called ‘cc force motion blur’ to your adjustment layer.

This is going to add motion blur to the layers underneath it.
In this case, you can now easily increase or decrease the amount of motion blur you need.

You can guess, the reason we need to precompose before applying the effect is because if we just put it on our main comp, it’s going to add blur to any other animation underneath.

But for the motion blur switch in your timeline panel, the only way you can reduce or increase the amount of blur is by tweaking it from your COMPOSITION SETTINGS.

You have different options; basic, advanced and 3D renderer.
Select ‘advanced’ and you’ll see an option with shutter angle.
The higher your value, the more your motion blur, and vice versa.

The only problem with this is that it affects your whole composition.

So now, we gotta look and choose which works for us.

I hope it’s clear enough.
Please if you need clarity on any other thing, you can reach out to me at davidologunde@gmail.com