There's a strong temptation for those new to video camera operation to leave their camera in fully automatic mode, and let the camera decide what the best settings are for all its controls. This frequently leads to poor (or at least mediocre) results, as the camera can't “know” for certain what the intended focus of the shot is, and tries to adjust to what it thinks may be the best overall results, instead of setting the camera for the best option for the mood of the shot and the lighting conditions of the point of interest.
When shooting professional-quality video, setting the camera into fully manual mode enables you to take control of the creativity of the shots and ensure that the video camera captures what you intend, and not get confused about unimportant features within the framing of the shot. Plus, you will avoid any surprises that often occur when the camera, left in “auto” mode, decides to change a setting in the middle of your shoot.
To use a camera in full manual mode, you need to understand how a video camera works, and how the settings for each aspect of the camera affect each other. Setting up your shot can often be a compromise between trade-offs, and knowing those trade-offs is important.
The settings that most interact with each other and affect the viability and artistry of your shots are the iris, shutter speed, and gain controls.
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Iris
The iris (or aperture, in photography terms) of a camera is the same as the iris of your eye—it's the small circular opening between lens and the camera that dictates how much light passes through the lens and hits the sensor. The standard measurement for the iris opening is the f-stop (or t-stop in cinema lenses—for the purpose of this article, we’ll treat f-stop and t-stop as the same thing). The larger the f-stop number (for example f/22), the smaller the opening, reducing the light allowed into the camera. A lens set to a small f-stop value (f/2.8) lets in a lot more light than when it's set to a large f-stop value.
You'll hear references to a lens being a “fast” lens. This refers to how low an f-stop the lens can be set to, because the lower the f-stop, the more light passes through the lens; and the more light that can pass through the lens, the lower the light levels needed on the subject to make a good image. This becomes important in low-light situations.
The f-stop setting used also dictates the depth of field of the shot—how much of what is in front of and behind the subject will be in focus. The larger the f-stop number, the greater the depth of field; things further behind and in front of the subject will be in focus. The smaller the f-stop number, the shallower the depth of field, which makes the background more out-of-focus and achieves more of that “cinematic” look.
What does all this mean? If you have a low-light situation, you generally need a lower f-stop setting to get more light into the camera to get a properly exposed image. But, your depth of field will be shallower, so keeping the camera properly focused is critical and more difficult. If you have a scene with a person walking towards you or away from you while shooting, this will be challenging with a low f-stop setting, as the depth of field may only be a few inches. In this situation try to add more light so you can use a higher f-stop to better manage focus on the moving subject, or adjust one of the other settings we’ll be considering in this article.
When deciding which f-stop value to use, you want to think about what effect you want to achieve. Is the background important to that segment of your video? Then you want to use as high an f-stop as possible to get greater depth of field.
Do you want to keep the viewer's attention on the person speaking? Then a shallow depth of field would help, blurring out the distractions of the background. In the context of a movie, you'll often see an establishing shot of a new scene with great depth of field so you can see where they are, and then when a conversation starts between two people, it will alternate between shots of their faces with shallow depth of field so you focus on the people.
Another common cinematic effect is the rack focus, which depends on a shallow depth of field, and thus a lower f-stop value. You have two subjects, one closer to the camera, one further way. The focus is set on one of the subjects, and then during the shot, the camera's focus is quickly and accurately changed or “racked” to the other subject.
Leaving a camera on automatic exposure, where it picks the f-stop for you, can work in an environment where the scene is evenly lit. However, shooting a presentation where the speaker is brighter than the background, or a concert or play where people are spotlighted, can often lead to the subject being over exposed and “blown out” (all white). Or if the lighting changes during the scene, the camera will be adjusting its exposure, making the scene look odd as the camera changes its settings. Setting the camera manually for the best exposure for the entire scene will deliver nice, consistent results.
Another aspect of the camera that also plays into depth of field is the focal length of the lens. Wide-angle lenses have a much deeper depth of field then telephoto lenses. So, another way to achieve a shallower depth of field is to go to a longer lens, and move the camera further back from the subject.
Shutter Speed
The shutter speed determines how long the shutter is open to allow light to hit the sensor of the camera for each frame. In the case of video cameras, this is accomplished electronically, not mechanically as in film cameras. The shutter speed is indicated on a dial or in a menu as either fractions of a second (for example, 1/60 sec or 1/500 sec). The slower the shutter speed, the more that moving objects in the shot get blurred, because they noticeably move in the amount of time the shutter is open. The faster the shutter speed, the clearer the moving objects are.
One might think that the clearest image in each frame would be ideal, and thus always use the highest shutter speed possible. However, that isn't the case. Your brain will find it very unnatural to see fast moving objects, “freeze-framed” at 30 fps. It creates a strobing or stuttering effect in the image. Those faster moving objects in the shot will look much more natural with a little blur from a slower shutter speed. However, if what you're shooting is footage of a baseball team to be used as confirmation of an umpire's call, then that fast shutter speed with everything clear as possible on a frame-by-frame basis may be more important than looking natural. Or, it’s common to use a fast shutter speed effect on action-packed scenes in a drama show to add to the feeling of “angst” they are trying to invoke. The CBS show Seal Team often uses this during assault scenes.
You need to think about the point of the shot, and the emotion you're trying to elicit, and pick a shutter speed that will give you that look.
However, the faster the shutter speed, the lower the amount of light that hits the sensor during each frame, and thus the more light you need on your subject to get a good exposure. (Or, lower the f-stop to get enough light into the camera, which also reduces the depth of field.)
Another way of indicating shutter speed that is common in cinema-style cameras is to use the concept of shutter angle instead of shutter speed. In mechanical film-based cameras, the shutter used to be a physical disc that had a wedge-shaped, adjustable opening in it. The disc would rotate in front of the frame of film, and size of the opening (specified in degrees of a circle as the shutter was a disc) dictated how much light was allowed to hit the film. A 90-degree shutter angle means that light passed through to the film for ¼ of the amount of time the frame was in position to be exposed. At a 24 fps frame rate, that means that the effective shutter speed is 1/96s. A 180-degree shutter angle at 24fps would be 1/48s shutter speed. The nice thing about shutter angle is that it gives you a consistent motion blur in your exposure. I tend to like the look of having a shutter speed at double the frame rate for motion blur purposes. If I change from 24fps to 30 fps, if using shutter speed settings I’d also have to update my shutter speed from 1/48th to 1/60th. However, if I’m using shutter angle as the way to specify the shutter speed, I leave it at 180 degrees for any frame rate I pick. Many cameras let you pick which style of specifying shutter speen you want to work in.
Setting a shutter speed lower than the frame rate (which some cameras allow) can result in odd things, however, because the shutter basically never closes. Exactly what a digital camera does with this depends upon the manufacturer—setting the shutter speed to ¼ second may result in an effective frame rate of 4 fps.
Gain
The gain control boosts the sensor's sensitivity to light. If you are shooting in an overly dark environment, boosting the camera gain may enable you to capture an image. However, it comes at a cost. Boosting camera gain also boosts the visual noise in an image, introducing random dots of off-colors throughout the image, particularly in the darker areas. Depending on the subject matter being shot, this can be very noticeable and make your footage look terrible. Think of the gain as a video amplifier like a sound amplifier. If a sound is not loud enough you turn up the volume on the amp, but when you turn it up it also brings up the background noise and hiss of the electronics. This is what you will see in your image when you “gain up.”
Boosting your camera gain should be avoided whenever possible—it's a tool of last resort for getting an image where otherwise your footage would be unusable.
So, Gain, Shutter Speed and F-stop all interact to set your depth of field and the amount of blur you get in moving objects. Think through your shots, and set your camera accordingly. Because once you've captured the images and left the set, you're stuck with the decision you made.
ND Filters
Most good video cameras come with built-in ND filters; or, you can purchase ND filters to attach to the front of the lens. ND stands for “Neutral Density,” and it's basically like sunglasses for your camera—it reduces the amount of light entering the camera evenly across the color spectrum. This is useful in bright lighting situations, like shooting outdoors in bright sunlight, on the beach, or for snow scenes. ND filters can help you recover some control over the depth of field instead of everything being infinitely in focus due to having to use your larges f-stop to reduce the light levels hitting the sensor. If you want to shoot a waterfall with a low f-stop to get a shallow depth of field, and want to use a slow shutter speed so the rushing water is blurred, you'd probably get so much light in the camera that the picture would be radically overexposed. Adding in ND filters will reduce the light entering the camera, enabling you to use the settings you desire.
Focus
While not a control that affects other settings, it's good to understand the problems that occur with leaving a camera on auto focus. Cameras typically focus on a specific point in the frame (often selectable via touch-screen, or older/less advanced camera just focus on the center of the image). While this can work for a straight-on shot, what happens if you need to frame a shot off to the side, or your subject walks across your framing catching you off guard? The video camera will then change its focus to the background behind the person you are shooting. If that background is far enough back from the subject, your subject is now going to be blurry as the camera focuses on the background. In lower light situations the auto-focus can have a hard time trying to determine what to focus on; the result is a “pumping” effect as the camera slightly changes the focus back and forth every second or two. This is very unsettling to the viewer trying to watch an interview or a presentation.
Today’s cameras often have facial recognition capabilities to keep the face of your subject in focus, and many work quite well. However, if your subject shifts around in their chair a little, the lens will unnecessarily track that movement and make small adjustments in the focus, which causes a noticeable “pumping” effect on the background of the shot.
I needed to edit a project for a client that someone else shot at a tradeshow. The main footage was an interview between two people. One person was framed on the right, the other was on the left, leaving the center of the frame open. The camera was set on auto-focus, and what the camera focused on was the equipment rack 20 feet behind the people. The rack looked great, but the interview subjects were so blurry the footage was unusable. Manually focusing on the subjects would have prevented this catastrophe. The videographer paying attention to the quality of the shot throughout the shooting also would have been a good idea.
White balance
White Balance is another important setting, but since this has been covered in another article on color correction written by Joe Barta and myself, I'll simply refer you to that article on the CPM website at https://www.churchproduction.com/education/color_correction/.
Hopefully, this article has helped you to understand what some of those mysterious knobs and controls are on your camera. Technology is always improving. The “fuzzy logic” in newer cameras is getting better at guessing what we want to see in our videos. Auto mode, which recognizes faces, focusing on them, and properly exposing them, is always improving, but it is still not as good as the human eye. With a little practice and experience, you'll find that turning all your settings to manual and taking the time you need to set the camera up properly for each shot will raise your videography skills to a new level.
Editor's Note (8/21/20): This is an updated version of an article originally published in 2012.
