I often adjust my esposure using the linear gradient tool, then I make a copy and want to put it on multiple files.
But sometimes after pasting the orienation of the gradient changed, if I copied it coming from below its applied from above on some photos not really doing what its supposed to do.
My idea is that I'm varying the portrait postion of my camera, sometimes my shutter points up sometimes down and that this is inteferring with the copy of the linear gradient tool.