Creating a fake backlight on a photo subject
I'm a newby that works mostly in Lightroom. In PS I attempted to take two b&w portraits, cut the subjects and pasted them to an 8x10 black background. I need to add a fake spot back light behind each subject to get the subjects to stand out from the black background. I can't find how to make a circle shape, feather it, dim it and place behind the subjects. I'm only getting stark edges and cant fade it or feather it. I tried shifting composite back to LR to add a backlight but it doesn't work there like it does on normal LR photos. I'm green but can someone get me pointed in the right direction to put a fake backlight on a portrait in PS.

