How half the width of a layer?

[Alexfitz22]

I have two of the exact same images, and i want to compare them in one, both have a layer, and different levels and curves, etc, how can i put a line down the center, and also half the first layer so that the second shows to the other side of it? This is simple in Premire with the crop tool, all you have to do is crop 50 on one corner, but I'm unsure of how this works in PS.

[JJMack]

Just add a layer mask to the top image layer 1/2 White the other half Black. All Adjustment layers should be clipped to the respective image layers.

[Alexfitz22]

I don't quite understand, could you break that down for me?

[JJMack · Accepted solution]

[Alexfitz22]

Thanks so much!