UNDERSTANDING EXPOSURE

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Figure 3.15 ND filters can reduce light when shooting in bright locations.

over-exposed. Although you should aim to properly expose all of your footage, it is more important to avoid over-exposing your shots than under-exposing them. Over-exposed footage contains no data and cannot be recovered in post-production. Slightly under-exposed footage is salvageable with some color correction.

Exercise

1. Set your camera to shoot at 24, 25, or 30 frames per second (depending on your preference).

2. Set your shutter speed to the appropriate setting (1/48 for 24fps, 1/50 for 25fps, and 1/60 for 30fps).

3. Set your camera on a tripod and shoot a scene with your ISO set at 800.

4. Adjust your aperture until you get a properly exposed image. What f-stop are you using?

5. Now, set your ISO to 1600. Adjust your aperture until you get a properly exposed image. What f-stop are you using?

6. Finally, set your ISO at 3200. Adjust your aperture until you get a properly exposed image. What f-stop are you using?

Did the f-stop increase or decrease and by how many stops in each set?

High contrast situations. There will be situations where not all areas of the foot- age will be properly exposed. For example, you may have a person in an inter- view with a window in the shot. In this case, it is important to expose for the person or main subject of your shot. This may cause you to over-expose the

Exposure, Composition, and Sequences 39

window. If you expose for the window in the shot, your source will be too dark. You must always be sure to properly expose for the main subject of your shot.

It is difficult to shoot in areas with high contrasting lights and darks. For example, if you are shooting outdoors, the areas in the shade will be signifi- cantly darker than the areas not shaded by a tree. Exposing for the area that is shaded will cause the other areas of your shot to be over-exposed. Conversely, exposing for the uncovered area of your shot will make the area under the tree very dark.

Figure 3.16a

Figure 3.16b

The subject is properly exposed, but the background

The background is properly exposed, but the subject

is blown out.

is under-exposed.

Tip: When you need to shoot outdoors (if your production schedule permits), shoot right after dawn or right before sunset. At these times, the sun is lower in the sky and the light is softer and more diffused. Additionally, the colors of the sky are bril- liant at these hours. Overcast or cloudy days are also good opportunities for shooting outside. Clouds act like a diffuser for the sun‘s harsh lights. Your scene will be evenly lit and easier to expose.

40 PA RT I I : Production and Post-Production Techniques

Figure 3.17 Shooting at dawn or at the end of the day will result in soft golden colors in your footage.

Exercise

Repeat this exercise in 10 different locations, both indoors and out. Place an object in the middle of your shot. For example, you can use a flower vase or a book. Move your subject from location to location and adjust your ISO and aperture so that your subject is properly exposed. Start with the proper shut- ter speed for your frame rate, pick a beginning ISO (800 is a good start), and then adjust your aperture to achieve proper exposure. Which situations gave you the most evenly exposed footage?

White balance. White balancing a camera ensures that you are capturing footage with the proper colors. Cameras determine proper color reproduc- tion based on the light source illuminating your shot. Light sources can

be natural such as the sun, or artificial such as fluorescent or incandescent lights.

Some cameras have presets for daylight balance (often denoted with a sun icon) or tungsten balance (a lamp). Some allow you to select the specific color temperature, measured in degrees Kelvin (K), of your light source. Improperly white balancing a camera will result in footage that is too blue or too orange in cast. For example, when you are shooting outside, you must shoot with the sun setting, or about 5600 K. When you are shooting indoors using house lights, you must use the tungsten setting, or about 3200 K. You must reset your balance whenever you change locations or shoot under a dif- ferent light source. Refer to your camera’s manual for instructions on how to adjust white balance.

Exposure, Composition, and Sequences 41

Figure 3.18 Different light sources have different Kelvin temperatures.