Filming underwater requires a lot of preparation. A great resource in Los Angeles is Hydroflex. It is an excellent place to rent an underwater housing, the owner is very nice, and the staff is incredibly helpful to answer any questions specific to your project. Testing all of your equipment with your camera operator and scuba operator is essential.
Important considerations before shooting underwater:
- How will you communicate with your scuba operator underwater? Hydroflex has underwater speakers you can use to direct your operator how to adjust frame, when to roll, etc.
- Where is the best place to shoot your underwater scene? Water quality is an important factor. Shooting in a controlled environment like a pool or a tank means the water will be relatively clear and it will be easy to plug in lights and black out parts of the pool with Visqueen if you need the pool to feel like a deep abyss. Shooting on location in an ocean, pond, or lake is challenging because you must first determine how murky the water will be. If the water is extremely dirty you will not see much of anything and be limited to mainly close-ups. This could be a cool effect, but it's important to be prepared for it.
- How long will your crew be in the water? If anyone will be in the pool for an extended period of time it is a good idea to have them wear wetsuits to regulate their body temperature. This applies even in a warm environment with warm water (particularly warm still water) because warm water conducts heat away from the body and can cause hypothermia.
- How do you plan to monitor from above what your scuba operator is doing down below? Remember to get an underwater BNC cable. Make sure everything is water safe! Especially camera cables running into and out of the water.
- How do the actors need to behave underwater? If there are any scenes requiring an actor to stay underwater without floating back up right away it may be a good idea to have weights in the pool that they can grab onto to prevent themselves from immediately floating back up to the top.
How not to shoot underwater:
- Using a DSLR inside of a "camera bag" that is "designed" for underwater shooting. Trust me, it's not. These bags fog up and make it impossible to control your settings or focus with the lens. If you are lucky after a lot of frustration, you at least can put the camera under the water and roll on things, but it is very stressful and not a good way to shoot anything accurately.
On this shoot we decided to keep things low budget and have a small crew. We had a scuba certified operator, a monitor, a Nauticam housing, and lit mainly from outside of the pool.
- LIGHTING: First and foremost, always use GFCI's on everything. Nothing is worth risking anyone's life when dealing with electricity near water. Every light (even and especially if it is outside of the water) needs to have a GFCI on it incase the light accidentally gets knocked into the pool (here is a great link to more about GFCI's). Underwater lighting is available from Hydroflex, but it may not always be essential for every shoot. A common way to shoot is using HMI's outside of the water to create a punchy backlight and maybe a light inside of the pool for fill. The next consideration is how much bounce will you get from the walls of the pool? Comparing a pool with white walls to black walls is a world of a difference. If you have not lit underwater before, it is a good idea to do an experiment in your bathtub with how light acts on objects in water. If you line the bathtub with a black garbage bag it will entirely change the contrast and look of the object in the water. Obviously the effect of this will be heightened in a small space like a bathtub, but it can help give a sense for what is happening on a larger scale in a larger pool with larger lights. Additionally if you want to create caustic networks reflecting on the outside environment you can also test which surfaces make this reflection more pronounced. In a shallower pool a darker surface will reflect the water networks better and a white one will wash them out.
- CAMERA: Rent or borrow the appropriate camera housing. For some housings it is important to know which lenses you will be using in advance since you will need to rent a specific lens attachment for the housing to match your lens. Most underwater housings are more compatible with wider lenses. Have the camera as set and ready to go before putting it in the water. Once it is in the water it is time consuming to change media and perform tasks that are usually fast outside of the water because the housing needs to be depressurized and readjusted.
Caution: Look out for bubbles your scuba operator may create while framing shots underwater. If they get into your shot it will ruin the cinematic illusion of your film and/or be a pain to remove in post.
Shooting underwater is a really fun way to see things from a new perspective. If you are shooting something only partially below the surface of the water consider simply using a fish tank or a pole camera. Pole cameras can be used to stick your camera underwater without having to go in yourself. They can be used for nature documentaries to avoid getting eaten by a shark or simply attached to a Go-Pro to get some cool perspectives. Even less invasive, if you are shooting near the surface of water, or in waves also consider using a splash bag, however it will not give you much control over the cameras focus or settings. There are many ways to create beautiful images underwater and your imagination is the only limitation. Stay safe!