 The main portrait photography light’s purpose is to give shape and to convey information.  if the background is near the subject, it's difficult to light separately.  ten to fifteen feet distance allows the background to "fall off".  getting as much distance as possible (within reason) is so that you can control the focus of the background.

 the fill light (flex-fill or white board) is on one side of the subject and not directly in front of the subject, it only illuminates the shadow side of the subject.  suspend it from a light stand, moving it closer and farther away from the subject.  use a fill card of some kind. In the studio, I use a sheet of 4x8 foamcore, leaning up against a light stand.

 The purpose of the background light in portrait photography is to relieve the shadows so that the idea

 Broad portrait lighting is when the main light is illuminating the broad side of the face and the shadow from the nose is being cast onto the short side of the face.  broad lighting is when the more exposed side of the face is facing toward the main light.

 Short portrait lighting is when the main light is coming from the short side of the subject and the broad side of the face is more in shadow.  If the subject’s nose is facing left and the light is coming from that same side.

 Rembrandt lighting is a lighting technique that is sometimes used in studio portrait photography.lightingphotography  It can be achieved using one light and a reflector, or two lights  Rembrandt lighting is characterized by an illuminated triangle under the eye of the subject, on the less illuminated side of the face.  It is named for the Dutch painter Rembrandt, who often used this type of lighting.Rembrandt

 main light is placed so far off to the side of the subject that the patch disappears and only half the face is lit, then it is considered to be “Split” portrait lighting.

 Butterfly lighting is named that because of the shape of the shadow created directly beneath the nose.  nose is pointing in the direction of the light, wherever it may be  light is high enough to cast a downward shadow, you end up with butterfly portrait lighting.

 photography is an art form and different artists will select different light positions.  to see both eyes lit. (except for split lighting) this lighting position will be different with each individual.  Do remember to use the transmitter for the DSLR to communicate with the studio lights  certain cameras can only go up to the sync speed around 1/250, the shutter speed cannot go higher than that while using studio flash.

there is a limit to how fast this shutter can be moved. Beyond a certain speed, the sensor can‘t expose the whole sensor simultaneously,