I have about 30 layers in After Effects and I need to apply a different Levels to selected layers. I thought of using Adjustment layer but the problem is that it applies to all the layers below and in my case it doesn't work because my target layers are all over the place and i can't change the order of them
I understand that Null object is used to control multiple layers but with position of the layer. Is it possible to do teh same but with color effects such as Levels?
what you need to do is add the levels effect to the null, then twirl down the layer attribute to effects>levels so you can see the histogram settings.
then on one of the layers that has the levels effect that you want to link to the null's, option-click (OS X) or alt-click (windows) the stopwatch for the histogram to enable expressions for that property. next, from the expression attribute that pops up, grad the pcikwhip (spiral icon) and drag it to the histogram property of the null.
now if you change the histogram on the null, it will make the same change on the other layer.
to easily apply the same expression to the other layers, right-click the histogram of the expression-linked layer and copy expression only. then select all the layers that have the levels effect that you want to link to the null's and choose edit>paste.
now the histograms of all those layers should be linked to that of the null's.
this will work for any keyframable property, so it would apply to nearly all properties in other effects.