I am trying to understand layers in photoshop...so I know the basics about adjustment, fill and mask layers, new and copied layers. BUT what I don't know and cant get my head around, is the basic 'rules'; why is it that sometimes I cant apply a new change onto my image. (for instance, I apply a color adjustment layer above a duplicate layer of the background, then how do I add a new layer to change the picture in another way, using the pixels?) I have tried adding a new layer and hitting COM+ALT+SHIFT+E to get the pixels up but then my change does not apply. If anyone understands what I am on about please help!!????