The “Art” of Underwater Video Lighting Techniques by Annie Crawley
Underwater we lose light as we descend. Red is the first color to disappear due to absorption. Housings come with red filters. A red filter transmits red from the color spectrum and helps correct the loss of ambient red light.
Manufacturers design their filter system differently. Light & Motion includes an internal flip filter in their housings. The “flip” means you can move a lever to position the filter in front of the lens or disengage the filter when it is not necessary. Whichever type of filter you use, you want to ensure it is always clean and free of debris or else when you go to look at your footage, there may be funky lines in every shot because of how this affects the light entering your lens. Also if the filter is not cleaned properly, everything may be out of focus. Filters should be cleaned with a dry lint free cloth. Sometimes in temperate waters or where you have green water, some filmmakers use a magenta filter. The same techniques apply when using these filters.
A great rule of thumb to use when shooting video is to put your red filter on as soon as you start descending and leave it there for wide angle video. By using the red filter when white balancing with or without lights, you will maintain a rich blue in your background, this is a great trade secret I discovered after years of practicing in different lighting conditions. Every rule made can be broken, and there are a few exceptions here as well. If you are shooting very close, wide-angle shots of silver fish with your lights, it's possible that the fish might get too close and appear to have a red tint in the photos. If you are shooting a silhouette directly into the sun, the sun may also appear with a red glow. When using the red filter, it is important to take some test footage to insure that it's appropriate to your shooting situations.
Once you understand the basics of your red filter, you must think about light underwater. The best light source that you can use during the day is absolutely free, our sun. When shooting underwater video many people do not check where the sun is located. Before hitting the record button, you must make sure the sun is at your back. During every dive I continue to ask myself, "Where is the sun?" This is important even on cloudy days. I always look up, around and at my shadows to figure out where the sun is before I press the record button. Shooting in caves or caverns or along reef walls can be so difficult because of the lack of sun. In these cases, you are not only losing the red, but the shadows cast a very blue light and block the sun. In these situations, you must get creative and dabble with backlight. Back lighting is when you break the golden rule of filmmaking and instead of shooting with the sun at your back, you shoot into the sun (or bright opening). This will create a very contrasty scene of dark shapes and bright light. Effective backlighting happens when there is separation between the camera lens and the subject as well as the light and the subject. Illuminating the entire reef with artificial light would be a feat, even for Hollywood.
Each of the example videos in this article have been created with the red filter on, sunlight and video lights.
It truly is magic to add light to a reef scene at just the right time of day so that the sun is balanced with the artificial light. When I use lights in this manner, about an hour before sunset, I don’t use the red filter because it would cause my scene to appear too red. Depth also affects the amount of sunlight that can penetrate. As light travels through the water column, the density of the water absorbs light.
On extremely overcast and rainy days you can often combine artificial light with sunlight effectively. I can’t tell you how important it is to experiment with conditions and your lighting system! On deeper dives you can sometimes get away with sunlight and artificial light, but regardless, you will definitely want to run tests with your lights.
Lighting for macro shooting is the easiest. During the day if I film macro and I am close enough to a subject for my lights to become the primary source, then I will not use the red filter—only my artificial light. I can do this because instead of the sun being my light source, I'm adding the light. The red is not lost because it is not being absorbed by the water column.
I like to have an extra light source for my model or dive buddy to carry because it adds another dimension to the diver. But the real reason I like carrying a third light source is because of how absolutely wonderful the scene looks when we can remove shadows and experiment with supplementary lighting underwater. When you shoot with one or two light sources, you often get shadows. When you shoot with three light sources, you can use the third as a fill light. I round up anyone who is willing to participate as my buddy. Just remember to explain the different hand signals and what you want them to do so there is no confusion. Usually they will use their light as the fill light and a little farther away from the subject than the main lights on the camera.
The creative possibilities are endless. You can turn off your
lights and shoot with only your buddy illuminating the subject. You can do top lighting such as this cuttlefish going to feed.
Although these techniques may sound advanced it is easy if you experiment. You can get excellent results once you understand the concepts.
You can use three lights of the same color temperature or you can mix and match the color temperatures. By doing this, you become the art director. I have a few lights I like to use and will pick and choose which effect I want to convey depending on time of day and the subject. I will often choose a buddy who has their own light that can be used as a third light and explain how much fun it is to work together underwater. Often at night the third light can round up animals for the camera, where bright lights shining from the camera would only scare the animals.
Get creative! Although there are guidelines you want to follow, there is no "set" way to light. You just need to make sure that you're not too close—with your articial light "blowing-out" your subjects and overexposing the scene with too much light. When filming, always check your aperture and distance to the subject to prevent an area from being overexposed. It's important to be mindful of the whites and lighter colors.
When you shoot with daylight balanced lights (such as LED's), you should try to white balance your camera underwater. To do this, you would want to bring a white slate down with you and white balance your system with your lights turned on.
The light beams affect your subject too. The "arc" of the light is defined as the angle of light coming out of the source. Lights designed for underwater filmmaking are usually flood beams and will not give you spot-type lighting the way that non-video lights do.
New LED lights are making underwater video even better! These new lights are more reliable, and easier to use than bulb and filament lights they replace. The newest LED lights also have more light output and multiple output levels that are appropriate for macro or wide angle work. It is an exciting time for underwater video!
In conclusion, it's important to understand the equipment that you're using. Finding the correct type of lighting and color filtration is also imperative to "getting the shot". Macro subjects have different lighting requirements, and shooting with a third or "buddy" light source can be a great way to ensure that you have plenty of light for minimized shadow or different lighting effects. If you have questions regarding underwater lighting and want to know which one is right for you, contact your local underwater lighting dealer (Light & Motion has a complete list of underwater imaging dealers on our Dealer Locator page found here. — Ed.).
Content taken from The Camera Coach, Your Guide to Creating Underwater Video: Chapter 7 on Lighting.
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Annie Crawley is an internationally renowned expert on underwater video. She has dedicated her life to helping others learn, grow and realize their potential. Annie's dream was to travel the world and create entertaining, educational programs. A child at heart, Annie wants to reach children of all ages whether 2 or 102, she encourages you to, "Dive Into Your Imagination, Dream and realize you too can live your dreams!"
