This mounting plate with a fixed industry standard spigot might be just what you were looking for to complete your photo booth project! It may also find a home on the wall or ceiling of your studio when you need all the space you can get.
The 6" extension ensures that you'll have lots of room to angle a light without bumping into your mounting surface. If you don't need all that tilt, and you'd prefer a lower profile mount, check out the Strobepro Wall Plate with 3" Spigot Extension.
Sturdy steel construction ensures that payload isn't going anywhere.