It is quite common in our business when lighting a set to light the actors separate
from the set. There is good reason for this. The big one is to keep the light on the actors from casting their shadows onto the background set,

Ever notice in soap operas on TV that the actors are generally away from the walls? The director of photography can light the background set so that it looks
attractive without worrying about actor shadows as long as they are a safe distance from the set lighting.

When we light the actors, we call this the actors block. As actors move around the set during their rehearsal with the director, the DOP (Director of Photography)
watches carefully and notes where there is significant dialogue in one area or
another and then he lights these areas so that the actors have what we call ‘good modeling”. This is to say that they are lit well.

Generally speaking the softer more diffused light (we call this the fill light) comes
more or less from the camera position with the key or main lights coming from the sides.

The idea of having the sun behind you falling onto the subject in front of you when shooting outside is mostly avoided when shooting professionally outdoors.
The simple reason for this is that the picture will look very flat and uninteresting
when lit this way.

I had a really good book on this some years ago called Lighting for TV and Motion Pictures by Harry C Box. If you can still get this book I would suggest you
read it cover to cover as it is loaded with how to’s on how to achieve good lighting.

Lot’s more good tips in my “Video Bible” which you can purchase from this site.

Cheers, Barry