Creating a fake backlight on a photo subject

[CraigT54]

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. 

[Bojan Živković · Accepted solution]

Put a black background at the bottom of the layers stack, a circle in the middle, and the subject on top. If you are using a Shape layer for the circle, select that layer and open the Window > Properties panel. Then, click on the Masks icon in the top left corner and use the Feather slider to soften the edges. To dim the circle, use the Opacity slider located in the top right corner of the Layers panel while the shape layer is selected.

In case you are using a pixel-based layer for the spot, convert it to a Smart Object for more flexibility, then apply Filter > Gaussian Blur to the Smart Object layer with the circle to soften the edges.

[CraigT54]

Bojan, thanks for the help.  You've got me on the right path.  Craig

[CraigT54]

Thanks, Bojan. And nice touch on the Gaussian blur. Craig