Keep the Sea at Bay: Underwater Housings for DSLR and Mirrorless Cameras
Point-and-shoot digital cameras have changed the reason many people scuba dive. In the early days, ocean explorers like Jacques-Yves Cousteau used scuba and cameras to explore the deep for scientific research purposes. Now, sport and hobbyist divers want to capture images and video to share their underwater experiences. Simple digital cameras in basic housings allow all divers to capture underwater snapshots and movies. However, many divers want to take their imaging to new depths.
Using a DSLR or mirrorless camera with interchangeable lenses underwater is the natural step to better imaging. Both camera types have advantages over point-and-shoot cameras, on land and underwater.
The sensor in a digital camera captures the image just like a frame of film does in an analog camera. The larger the sensor, the more space there is for larger pixels—this is more important to image quality than the number of pixels. With large pixels, you get better dynamic range and color depth. The images will have less noise if you expose at higher ISOs.
Better Manual Control
All DSLR or mirrorless cameras offer manual exposure control, but not all point-and-shoot cameras do. Many point-and-shoot cameras offer manual control from the menu, but this is often difficult to access in a housing. Most DSLR or mirrorless cameras offer access to this control with dials and buttons.
Interchangeable Lenses with Better Optics
This is the key reason to move up to a larger, more professional camera for underwater imaging. Lenses that you buy separately from the camera will be sharper and create images with more contrast. You pick the lens that is best suited for your subject and environment.
DSLRs are designed the same as single lens reflex film cameras. They have a mirror in front of the sensor that reflects the image up to a prism for viewing through the viewfinder. This permits the photographer to peer into the viewfinder and see the view through the lens, so he or she can compose the image according to their particular sensibilities. In order to accommodate a mirror and prism, the DSLR needs to be larger than most point-and-shoot cameras.
Mirrorless interchangeable-lens cameras use the LCD screen or an electronic viewfinder. They do not have a mirror-reflex optical viewfinder. This is why they can be made more compact. Smaller cameras mean smaller underwater housings. With luggage restrictions on airlines getting tighter, saving space and weight is important to the traveling diver.
So, which camera is best for you? There are many great DSLR and mirrorless cameras on the market. The first key feature—there has to be a housing that fits your needs. This sounds obvious, but divers buy cameras and then are shocked when they discover there is no housing available.
You want a camera that will suit your needs on land. It is important to be able to operate your camera controls blindfolded, and purchase a camera that you can use above and below the water line.
Try to select a camera body that you can afford to own in duplicate. One gets used topside, and the other stays in the housing. This way, when a blue whale passes close to the boat, you do not have to remove one camera from the housing and change lenses. The second camera is your underwater backup. If there is a leak and the housing gets flooded, you’ll have a spare camera body. Between lenses, housings, ports, and lighting, the camera body is sometimes the least expensive component. Housings are usually only compatible with one camera model. Sensor size is important, but many DX format and Micro Four Thirds-size sensor cameras also produce great results, and the cameras are physically smaller.
Housings for DSLR or mirrorless cameras with interchangeable lenses should allow you to access all the important camera controls easily. The better housings do not have a built-in lens port. They accept interchangeable ports, which accommodate specific lenses and are generally not included. Lower-end housings do not have interchangeable ports or the same flexibility or quality.
It is important to consider the material from which the housing is made. Aluminum housings are the most expensive, are robust, and rated to deeper depths. If you are a tech diver exploring deep water, you will need an aluminum housing. Both Aquatica and Sea & Sea manufacture them.
Aquatica housings are manufactured in Canada. Ports, extensions, and gears are available separately to accommodate a wide variety of camera lenses. They offer both manual and autofocus macro ports. For wide angle, you can get 4, 6, 8, and 9.25" dome ports. Zoom gears have to be purchased separately. The zoom gear is placed on the lens, around the zoom control on the lens. The gear interacts with a control on the housing. When you turn the knob, the zoom control on the lens turns. Aquatica housings are depth rated to about 300', and many can be upgraded with stronger springs, installed on the controls, allowing for operation down to 425'.
Aquatica offers a variety of strobe connection options. The company offers dual Nikonos bulkheads as standard equipment. This allows you to connect two strobes with two Nikonos sync cords. These housings contain a circuit board, and by repositioning the switches, you can have two pins operating for manual strobe control, or all five or six pins for using an external TTL converter. There’s also an Ikelite bulkhead available, with two pins for manual or all five pins for using an external TTL converter. Housings for cameras that have a built-in flash can be purchased with single or dual fiber optic cable ports. In this case, the camera’s built-in flash fires and the light travels up the fiber optic cable and to the external strobe's slave trigger.
Aquatica offers the SURVEYOR moisture and vacuum sensor alarm. You could buy a housing with the alarm installed or add it later. This system includes the Surveyor moisture and vacuum sensor circuit, a pressure valve, and vacuum pump. The SURVEYOR circuitry integrates a water detection function that remains on when a battery is inserted. Should the slightest amount of water make contact with the sensor probes, it will trigger an alarm, using both an audible signal and a rapidly flashing red LED light. To fully test the sealing integrity of the housing, you use the optional vacuum pump and pressure valve to create a vacuum. All you have to do is push the On button and attach the pump to the valve. After pumping out all the air, a green LED light blinks every five seconds. This way, you know the SURVEYOR system is monitoring the housing and that it is safe to enter the water. If the vacuum is lost, the alarm warns you with an audible signal and a rapidly flashing red LED light. Creating the vacuum seals the housing, so it is impossible to open by accident, which should make any diver feel more secure.
Sea & Sea housings are manufactured in Japan and designed for maximum functionality. They produce both aluminum housings in the MDX line and black polycarbonate in the lower-cost RDX line. For both housing lines, there are number of ports, extensions, zoom gears, and focus gears to buy separately. Sea & Sea MDX housings are depth rated to about 330', and the RDX series to about 200'.
Sea & Sea housings have fiber optic cable ports for strobe connections. If you want to use a sync cord, optional connectors are available, depending on the housing. Another option is the Optical YS Converter. This compact device fits inside the housing, attached to the camera’s hot shoe. It converts the camera's TTL signal to a light signal. Fiber optic cables are used to fire an external slave strobe—you can choose between manual and TTL exposure control. Using the Optical YS Converter gives you more accurate TTL than using the camera’s built-in flash, and you do not have to wait for the camera’s flash to recycle before taking your next photo.
Clear polycarbonate is a very popular material for housings. The material is strong, corrosion resistant, and easy for manufacturers to fashion into housings. Since the housing is entirely—or at least partially—clear, if you have a small leak you should be able to see the problem and get to the surface before the situation gets critical. Ikelite, Nimar, and Polaroid produce clear polycarbonate housings.
Polaroid housings do not have interchangeable ports, but are dedicated to specific lenses instead. Nimar housings are manufactured in Italy. You can buy these housings for your camera’s kit lens with or without a port. Ports for other lenses are available.
Ikelite housings are manufactured in the United States. The company produces housings for more camera models than most other housing manufacturers. Ikelite housings have standard acrylic macro and 6" dome ports. These ports are for specific lenses and have the port extension built in. The housings are also available in a modular system. This system has a glass macro port and acrylic 8" dome. You have to buy the port extension separately for each lens. Two different-sized zoom assemblies are included with most housings that Ikelite produces for interchangeable-lens cameras.
Ikelite housings for DSLR cameras do not allow you to pop up the camera’s built-in flash. External strobes have to be connected to the housing with an Ikelite-style sync cord. Select mirrorless camera housings do allow the camera’s flash to be fired for the purpose of triggering an external strobe. This gives you the choice of a fiber optic cable or sync cord for firing external strobes. When using Ikelite strobes, TTL is supported when using a sync cord. On DSLR housings, you have exposure compensation and manual strobe settings that you can adjust with a dial on the housing. On mirrorless cameras, TTL exposure compensation can be adjusted through the camera.
Both Olympus and Nikon produce housings from colored polycarbonate. The Nikon housings for certain Nikon mirrorless cameras do not have interchangeable ports, and this also applies to most Olympus Pen and OM-D series camera housings. You can remove the built-in port in some cases, and some third-party companies sell other ports for these Olympus housings. Olympus housings for the OM-D E-M1 and OM-D E-M5 do have an interchangeable port system.
Equinox housings are manufactured in the United States, from thermal-based polyvinyl carbonate. Originally for video camcorders, Equinox now produces housings for DSLR or mirrorless interchangeable-lens cameras. The process takes a PVC cylinder of the right size and puts a dome port on one side and a clear back plate on the other. The included dome port is for the best wide-angle lens to use underwater, on high-end camera models. Entry-level camera models will have a dome port for the kit lens. Custom lens ports are available. Holes are drilled into the housing to access all-important controls with O-ring-sealed buttons, knobs, and levers. Some of the housings also have a bulkhead connector installed for attaching strobes with a sync cord, while others will accept an optional bulkhead for this purpose. Equinox housings are heavier than aluminum or polycarbonate housings. This extra weight does have an advantage when shooting video. It is easier to hold the housing steady.
Lenses and Ports
All water, no matter how clear it seems, will have particles in it, so the less water there is between your lens and subject, the cleaner your images will look. This is why wide-angle lenses are so important in underwater photography. In general, you do not want to push the shutter button unless you are two feet away or closer. So, how do you capture a whale shark? You have to use the widest lens possible. The focal length of the lens you use will depend on your camera’s format. If you are shooting with a full-frame camera, a 17mm lens will have a wide 104-degree angle of view. But on an APS-C format camera, the angle of view of the same lens is only 79 degrees. Since we want to work as closely as possible to the subject, we want lenses that are able to focus close. Medium-wide lenses could be used for mid-size subjects, since the lens you use also depends on your subject’s size.
When using full-frame cameras, the ideal wide-angle lens is between 14mm and 20mm in focal length. Popular rectilinear lenses for Canon full-frame cameras include the Canon EF 16-35mm f/2.8L II USM, EF 17-40mm f/4L USM, EF 14mm f/2.8L II USM, and EF 20mm f/2.8 USM lens.
Most fisheye lenses have an angle of view of 180 degrees. They are very useful underwater and have a different look than rectilinear lenses, distorting the image by making straight lines appear curved—especially at the edges of the frame. Popular fisheye lenses for full-frame Canon cameras include the Canon EF 8-15mm f/4L Fisheye USM and the Sigma 15mm f/2.8 EX DG Diagonal Fisheye.
Popular rectilinear lenses for Nikon full-frame cameras include AF-S NIKKOR 16-35mm f/4G ED VR, AF-S 17-35mm f/2.8D, and AF NIKKOR 20mm f/2.8D. Fisheye lenses include the AF Fisheye-NIKKOR 16mm f/2.8D and Sigma 15mm f/2.8 EX DG.
On an APS-C-sensor camera, we want lenses in the 10mm -14mm range. The Tokina 10-17mm f/3.5-4.5 AT-X 107 DX AF Fisheye Lens is among the most popular for Nikon and Canon cameras. Besides having a 180- to100-degree angle of view, the lens has a minimum focus distance of 5.5". The Tokina AT-X 116 PRO DX-II 11-16mm f/2.8 is also a heavily favored lens for underwater.
For Micro Four Thirds cameras, the Olympus M.ZUIKO Digital ED 9-18mm f/4.0-5.6, Panasonic Lumix G Vario 7-14mm f/4.0, and Panasonic Lumix G Fisheye 8mm/F3.5 are some of the best for wide-angle subjects.
Almost every housing manufacturer produces a port chart. Other lenses than the ones mentioned above can be used underwater, but they have to be listed on your housing’s port chart. Everything underwater looks 25% closer and larger. For this reason, it is best to use wide-angle lenses behind a dome port. Dome ports correct this size distortion. When using rectilinear lenses, soft edges can be a problem. In most cases, the larger the port is, the sharper the edge of the frame will be. Since fisheye lenses produce curved images, edge sharpness is not an issue. For this reason, even small 4" domes can be used.
For tiny subjects, macro lenses are the best tool. For full-frame cameras, lenses in the 100mm range are best. This way, you have some distance and won’t frighten or alarm your subject. On APS-C cameras, 60mm lenses work best. These lenses will have an angle of view equivalent to that of a 90mm lens on a full-frame camera. This way, if you see a medium-sized subject, you should be able to pull back but still be close enough to capture an image. For Micro Four Thirds cameras, the Olympus M.ZUIKO DIGITAL ED 60mm f/2.8 Macro and Panasonic Leica DG Macro-Elmarit 45mm f/2.8 are good options.
Macro lenses should be used behind a flat port. This way, the 25% larger size distortion can be employed to your advantage. Since focus is critical when shooting close, many photographers want to be able to focus manually. Most housing manufacturers have special flat ports with manual focus control, and focus gears need to be purchased. Just as with the zoom control, the focus gear is placed on the lens, around the focus control. The gear interacts with the focus control on the port when you turn the knob.
Getting a housing system for a DSLR or mirrorless interchangeable-lens camera is an investment. There is a task loading, and a steep learning curve. Handling the equipment is like driving a sports car—it will take time and practice to use it to its full potential. To create stunning images, we have only covered half the story. We have to add lights and arms to control them. In our next article, we will talk about underwater lighting in greater detail.