Welcome to the Lights Film School video tutorial on using flags. A cinematographer once said that “Great cinematography is not about knowing how to turn a light on, it’s about knowing how to shape and mould that light”. The intention of his video tutorial is to help you understand that shadow is light’s creative equivalent.
Let’s begin by talking about what flags are:
Flags are pieces of black duvetyne held together by metal frames. Flags are generally held up by c-stands in an effort to cut or shape light and provide “negative fill”.
It’s important to mention that when using c-stands you should first position your flag exactly as you want it with the c-stand joints loose. Then when your flag is ready, tighten the c-stand joints in order to secure the precise position of the flag. This will not only help you precisely establish where your shadows will fall, but it will also save you a lot of time during your setup.
Many independent filmmakers rather than using black fabric flags and c-stands, will instead use tripods, clamps and black foam core. A large piece of black foam core can be purchased from an art supply store for around $10-$15 and it will have essentially the same impact. In fact, virtually any opaque object can be used to flag light.
Where to position your flag?
Knowing how and where to position your flag is important. A flag that is positioned close to the surface the light is being project onto will appear dark with clearly defined shadows and edges. However, as the flag starts to move towards the light source the shadow will become slightly more diffused with softer edges.
Moving your flag.
Once you have your flag in position you can start controlling where your light falls by re-positioning your flag. Here we wanted our flag close to our light to give a soft shadow with gentle edges that “feather out”.
There are many applications for using flags but let’s discuss how we can use flags to control the spill of light while filmming a subject.
Notice how we have a subject in frame and we are moving the flag back and forth. You can see the impact this has on the image. However, it should be noted that it’s easier to control flagging different layers if there is a noticeable separation of depth. So let’s pull our subject off the wall a little bit… Much better. Here you can see how the flag impacts the image as we move it back and forth. The flag’s purpose is to help filmmakers highlight the parts of the frame that are most important to them while muting the areas that are less important or distracting. Picasso even said it himself when he stated that “Art is the elimination of the unnecessary.”
But now let’s start from scratch building a shot from the ground up.
We’ll begin by turning our overhead lights on so you can see the room before we start to design our light. Now let’s walk around the set so you can see how the flags are blocking the light. This flag, directly in front of us, is stopping the 1K zip light from hitting the back wall. And this other flag is going to be stopping the light from hitting our subject. Notice there is only the smallest sliver of light shining through as we move in front of the flags. Most of the light is being completely blocked. We can now manoeuvre these flags to shape the light to our liking.
let’s go to black.
Notice how these two flags stop all of the light being projected from the 1K zip light from hitting the background. Now let’s introduce our subject to the shot. As predicted, only a sliver of light is making it’s way though the flags.
Now let’s look at what happens when we open up the background flag. Notice it has no impact on the subject who is still only being lit by a small sliver of light.
If we open up the flag on the subject the following will result.
But now let’s block the light on our subject and our background again. At this point we’ll turn on a small practical background light. We’ll also open up the flag hitting the subject so a sliver of light comes through.
Because we’re getting closer to our final composition lets now also turn the rim light on.
Let’s walk around the studio again. Here is the flag flagging our actor. Watch what happens when we move it right to left. Notice it has no impact on the background.
Now let’s look at the other flag that’s stopping spill from hitting the background. Watch what happens when we open and close that flag. Again, notice this has no impact on our subject. Having this flag stop the spill of light from hitting the background allows us to keep our background darker giving us more contrast and a dramatic and moody look. When we open the flag up the composition becomes flatter.
So now let’s punch into our final framing. Let’s look one last time at the impact that the flags have now that our rim light, background light and our key light are all turned on. Here we move the flag controlling light on the subject back and forth. Again, notice this has no impact on our beautifully lit background. Now we can experiment by opening up the background flag a little bit… But it was nicer with a darker, richer background, so let’s put that back. And here you have it… your final shot!
The idea here is to think about lighting in terms of layers and depth. Light your background, middle-ground and foreground separately by using flags to help you control the spill of light.