Not only does a housing need to be dependable at keeping your camera dry, but it must offer reliable control of key camera functions from outside the housing. There are basically two styles of controls available: mechanical and electronic.
Mechanical controls typically employ sealed control rods that allow you to physically manipulate the camera’s buttons and knobs from outside of the housing. Mechanical controls have the advantage of being reliable and relatively inexpensive because of their simplicity. The drawback is that each control requires another hole and seal assembly through the housing, possibly increasing the risk of a flood if one of these fail and leak. Also, mechanical controls are somewhat limited in what functions of the camera they can access and their fixed positioning most always limits their use with one specific model of camera. Gates and Ikelite are two makes of housings that incorporate mechanical controls with great success.
Electronic controls offer more flexible and sophisticated control over camera functions. Nearly all housings incorporating electronic controls utilize the camera’s LANC port, meaning they are designed around the Sony line of camcorders. Electronic controls can enable access to camera menus and functions impossible to reach using mechanical controls. Additionally, the buttons used to activate the electronic controls are typically placed on the hand grips of the housing where they are quickly and comfortably manipulated. The main disadvantage of electronic controls is their reliability. Push button switches and electronics must be sealed. One drop of water leaking into the electronic controls can render them useless. Amphibico, UnderSea Video, and Ocean Images are a few of the prominent housing companies utilizing electronic controls in their designs.
Regardless of whether a housing has mechanical or electronic controls, it needs to allow control of a minimum of camera functions to be worthy of consideration. Below are three functions that need to be controlled underwater.
This allows you to turn the camera power On or Off. You’ll want to be able to turn it off during boat rides and surface intervals without opening the housing.
With the camera On, this toggles between recording video to tape or standby mode.
Focus lock or momentary auto-focus
Most cameras use auto-focus by default. This is Ok to use as long as there is the ability to at least lock the focus while diving. Low-contrast and sediment in the water can cause auto-focus feature to continuously ‘hunt’ for a focal point, resulting in annoying video that keeps going in and out of focus.
Notice zoom control isn’t included as a necessary underwater control. Although most housings support zoom control, it’s quite useless underwater unless you are using a tripod. While underwater, one should just have the zoom set to its widest setting that doesn’t show vignetting at the edges. If you want a closer shot of something underwater, the right thing to do is get closer, not zoom in. More on that in the Basic Shooting Techniques section.
Beyond the basic controls, there are several other functions the more experienced videographer will want to control to get higher quality results. Such functions are:
Full manual control over the camera focusing.
Manual White Balance
The ability to calibrate the camera to a white reference underwater. This helps to get true colors underwater.
Manual Exposure or Exposure Compensation
Full manual control over the exposure (aperture) or the ability to bias the auto-exposure up or down.
The ability to zoom in closer to a subject underwater can be useful when shooting a macro subject with a tripod.
Changing to a faster shutter speed has usefulness in capturing fast moving subjects.
Full Menu Control
Being able to have full access to a camera’s menu is a luxury for most. However, one very useful benefit of full menu control is being able to switch between 4:3 and 16:9 wide aspect ratios while underwater.
VTR mode is the camera’s playback mode used to cue and review video you’ve shot on tape. Advanced and professional underwater shooters like this feature because it allows them to check if they captured the shot they wanted before leaving the water.