Most rules of topside video are applicable when shooting underwater video. Composition involves the same elements and guidelines such as the rule of thirds, leading looks, leading lines, and color balance. However, the underwater environment adds some new challenges to conquer in order to get decent video.
Here are the sections of this article to read over for basic video shooting techniques:
»Be comfortable and safe
»Find the right angle
»Get your colors back
Be comfortable and safe first
The most important thing to remember while diving with a video camera is your responsibility as a diver comes first and video second. Be safe and respect the reef environment. Initially, try making a dive with your housing without the camera installed. Put some weight in the housing to simulate the weight of the camera and make a dive or two. This helps you gain experience with diving and controlling your buoyancy while toting the rig without the distraction of actually shooting video. It also gives you a chance to check for housing leaks before installing your camera, which is a good thing to do anyway with a new housing. Once you feel comfortable handling the housing in and out of the water, you’re likely ready to load the camera and start shooting video.
Get as close as safely possible
One of the fundamental rules of underwater still photography applies to video as well: Get as close to the subject as safely possible. Let’s discuss some of the primary reasons to do this.
Water negatively distorts images in two significant ways. First, it strips warm colors from the image. Second, particles in the water reduce clarity. The more water between the lens and the subject, the more severe both of these effects. Getting close means you’re shooting through less water, which gives you better clarity and color. The best underwater video is usually shot with the subject at 1 to 5 feet from the lens.
Getting close also gives the advantage of getting more stable video. Although it’s possible to use a tripod underwater, most recreational divers shoot video holding the camera in their hands while remaining neutrally buoyant. A hand-held camera is more prone to produce shaky video, but there are things you can do to help mitigate the ‘shakes.’ First, don’t zoom the camera on the subject. Instead, physically move in as close as you can safely get to the subject and shoot the subject with the lens zoomed out at wide-angle. With the lens at wide-angle the effect of camera motion on the video is minimized. Take a look at the figure below. Assume that A and B are the same subject at different distances from the camera’s lens. If you wanted to compose the subject at distance B to be the same size in the frame as at distance A, you’d need to zoom the lens farther in on the subject. If you think of a line from the lens to the subject as a lever, you can understand how distance multiplies the effects of shaking at the camera as you get farther from the lens.
Find the right angle to shoot from
When picking a subject to shoot, one must give ample attention to what angle to shoot the subject from. This can make all the difference between a shot that looks amateurish and one that looks professional. Remember, you chose what to reveal to the viewer of your video through your composition, and the angle of the shot is an important part of that.
The most common mistake beginning underwater videographers make is shooting straight down at a subject from above. This results in a flat looking image with no depth. A much better angle is to get slightly below the subject and shoot it horizontally at a slight upward angle. This will put more depth in your image and can greatly ‘dramatize’ your subject. A lower angle also gives you the option of positioning the subject in a sunlit blue water background, making it stand out with more contrast. The figures below illustrate a poor angle of composition and a much improved one.
Get your colors back
The more light that travels through the water, the more the warm colors (reds) get filtered out. When sunlight is your primary light source, you lose more of its warms colors the deeper you dive. The result is subjects appear to have a blue cast to them and those subjects, which are actually red, appear to look dark green to the human eye. So, in other words, you don’t see the subject’s true colors in this situation.
Technology provides a few techniques to add the warm colors back into the light and thus our video. One of the simplest and most cost effective methods is the use of a color-correcting filter. This filter compensates by adding reds back into light before it enters the cameras lens. Most video housings offer this as either an internal flip-down filter or as an external wet snap-on filter that fits over the housing’s lens port. The filter should be used at depths below 10 feet when the primary source of light is the sun. If your housing has an external wet color correcting filter, make a habit of taking it off after entering the water and gently wiping out the bubbles on both sides of the filter and the port before you begin shooting video. Bubbles stuck to the filter or port can ruin your shots. It’s worth mentioning to repeat this exercise if you pass through another diver’s bubble plume later during the dive.
Another way to add the warm colors back into your video is to use underwater video lights. Video lights are obviously essential on very deep dives, cave and wreck penetrations, and night dives when they are the primary source of light. However, video lights can also be used in conjunction with sunlight to boost light and color in the foreground. In this situation, the artificial light generally only has a useful range of 3 to 4 feet, so make sure you stay close to your subjects. Note, you can use the color correcting in a balanced light situation (sun combined with artificial light) if you keep the subject at least three feet away from the light source. Any closer and you’ll end up with too much red in your video. Never use the color-correcting filter when the artificial light is your primary source of light (i.e. night dives) unless you want completely red video.
Finally, a camera’s manual white-balance feature can be a great help in reclaiming true colors underwater. To manually white balance a camera underwater: Find a reference subject that is known to be close to true white, position the white reference subject in light that is similar to what you will be shooting in, zoom the lens to fill the frame with this white subject (focus doesn’t matter when doing this) and activate the manual white balance. What this essentially does is calibrate the camera to know what true white looks like underwater in certain lighting conditions. You can white balance with color correcting filters in place and also when using video lights. The key is to remember that you are calibrating to a specific lightning condition. So, if conditions change (i.e. you remove the filter, turn off the video lights, change your depth by more than 10 feet, etc.) you need to repeat the manual white balance. Performing manual white balance can be considered more of an advanced technique because of the attention it requires. One way to make it easier is to bring a white slate or paint a white area on your fins to have a handy white reference available. However, when you’re beginning, it’s probably easier to just use the camera’s auto-white balance mode. Once you gain experience and skill, you can begin to experiment with using manual white balance.
Most beginners’ use the video camera’s auto-focusing exclusively. This is okay when starting out. After gaining confidence and experience shooting video underwater, you want to take advantage of focus lock and/or manual focus.
Auto-focus works by detecting contrast between subject and background and then ‘hunting’ the focus to sharpen the boundary between them. Auto focus has its limitations and these are even more apparent underwater than topside. When there are particles suspended in the water column between the lens and the intended subject, auto focus can begin to ‘hunt’ and then decide to focus on one of the particles instead, putting your desired subject out of focus. Also, marine animals survive by adapting their color to their surrounding environment. Thus as your subject, these critters have a low level of contrast with the background making it hard for auto-focus to detect and lock on.
Being able to lock (disable) the auto-focus feature underwater greatly helps to mitigate your frustration when auto-focus begins misbehaving as described above. One technique is to use auto-focus to first correctly focus on some objects with high contrast (i.e. the edge of your fin against the water or sand) then lock the auto focus at that point. With the focus now locked, frame your subject and physically move the camera closer or farther from it to move the camera’s plane of critical focus directly over the subject. You’re using your eyes in the viewfinder to monitor the sharpness of the focus and your camera to subject distance to adjust it. If your rig has full manual focus capabilities, that’s even better. Compose and frame your shot, then use the manual focus controls and your eyes on the viewfinder to focus as required.