The day I stop learning about lighting will be the day my EKG goes flatline. There's an extraordinary amount to learn and absorb, and I doubt I'll ever learn all of it. That's okay, because it means I'll never run out of new things to learn. My most recent fixation is on the one light many think about the least: the fill light.
I've gone through periods of my career where I focus on different lights and how to use them. I started by looking at key lights: how to place them, what works on different kinds of faces and what doesn't, how big they should be in relation to the actors, etc. Then I spent a lot of time on backlighting and edge lighting: where are the best spots to place backlights, should I use both a back light and an edge light or use one light to do both jobs, when can a back light become a key light on the next setup, etc.
It took me a bit longer to concentrate on fill light, as early on in my career I was focused more on shaping the bright areas of the frame than I was on filling in the shadows. It's only been in the last ten years or so that I really came to learn the power of the fill light.
About that time I participated in an online conversation on the Cinematography Mailing List that resulted in an offline exchange with a famous director of photography. "The fill light is, of course, the most important light and yet it is also the most difficult to place," he said, and I, of course, agreed completely while at the same time having no clue as to what he meant. I should have simply asked him, but for some strange reason I didn't, preferring to imply that I knew exactly what he spoke about. (Strange. Ah, youth.)
The good news is that I started paying a lot more attention to fill light, and I am now of the opinion that it is possibly the most important light on the set.
I'm now going to do my best to tell you why.
First, a short story: I was day-playing as an operator on a well-known (but not not terribly good) TV series with a very talented director of photography. I noticed that he always filled from the key side. That technique had been somewhat on my radar but I hadn't practiced it religiously and had not yet discovered what a fabulous technique it is. He would set a key light for the scene (raking sunlight, a large soft source from the side, a bare light bulb--whatever) and then place the fill light near the lens on the same side as the key light. Often it consisted of a small light through a frame of Lee Opal or 250, with the bottom corner of the gel frame at the top right corner of the matte box. (This kept the light close to the lens axis, for reasons I'll go into shortly, while allowing the camera assistant to see underneath it.) Regardless of how harsh the key light was he never moved or diffused it; he simply filled from the same side, near the lens axis. The results were consistently beautiful and natural.
First I'm going to run through a number of different techniques and show diagrams for each. At the end of the article I'll show you some examples from my own work. I don't have good, recent examples of every technique because, honestly, I don't use every technique I'm going to explain; but I'll show you the examples I have (or that I'm willing to show) and encourage you to take the knowledge you glean from my diagrams and experiment on your own.
You'll learn more by doing that anyway. I'm firmly of the belief that learning is primarily the act of becoming aware of something and looking at it in a new way. I hope the knowledge that I impart will allow you to become more aware and observant of this element of lighting so that you can improve your use of it.
Turn the page and let the diagrams begin...