Complex sentence: Typically the opening in the center ranges from 4 to 7 inches (to allow the light source to come into the softbox or other modifier) The most common ring types are Bowens, Profoto and Alien Bees.
Split into simpler sentences: Typically the opening in the center ranges from 4 to 7 inches, allowing the light source to enter the softbox or other modifier. Common ring types are Bowens, Profoto and Alien Bees.