Buyers Guide to Digital Underwater Photo Gear
Digital photography has drastically changed the way the world takes photographs. From the pro to the individual taking family snapshots, digital imaging is now the most popular option. Film is still used in certain specialized applications but now digital photography is the norm. Very few new film cameras are being produced, but every month manufacturers release new and improved digital cameras and accessories.
In the world of underwater photography, digital imaging has changed the landscape. The biggest advantage is seeing your photos before you even surface. This way you see your mistakes, make corrections and re-shoot. Back in the days of film, many a photographer would return from a trip, process their film, and be disappointed. A wrong setting or some other uncorrected problem could have the photographer returning from a trip without images. Aside from being able to see and evaluate your pictures immediately, the price and size of many digi-cam camera housings are attractive: divers are now willing to try underwater photography for the first time.
Types of Digital Cameras and Using Them Underwater
For our purposes, we need to divide digital cameras into two groups: Single lens reflex (SLR) and digi-cams. SLRs look like and are the size of SLR film cameras. They allow you to change lenses, they have advanced features, and they are faster than most digi-cams. These cameras require a good working knowledge of photography; they are also large and expensive. Digi-cams are small point & shoot cameras with built-in lenses and limited controls. These cameras are much easier to use but have limitations.
Digital cameras in both categories keep getting better while prices keep getting lower. Many camera manufactures now produce economical housings for many of their digi-cam models. Third party companies produce housings for a variety of digital cameras in both categories; these vary in price from $150 to $5000. A low-end gear configuration is good for someone starting out in underwater photography. An inexpensive digi-cam camera in an economical housing is great for underwater snapshots. It can take great photos if used within the gear’s limitations. As you grow in both your land and underwater photo skills you will want to upgrade your equipment.
A disadvantage with using digital cameras underwater is that the controls are accessed mechanically. So whenever you want to upgrade to a new camera, the smallest change in size or control button position means you have to buy a new housing.
Closer is Better: Macro
One of the paramount concepts in underwater imaging is to get as close to your subject as you can. Water is denser than air. The farther away you are the less contrast and color your images will have. As a beginning UW photographer, taking photos of small fish and objects will give you better results. Most digi-cams have macro modes and allow you to get very close. Sometimes a close-up lens on the outside of the housing helps achieve higher magnification while being farther away from your subject. This way you don't have to get so close to your subject and possibly scare it away.
|Macro photos of stationary or slow moving subjects are the easiest to photograph
For digital SLR cameras you want to use a good macro lens, and on your housing you will need to use a flat port. Since focus is very critical when working close, many SLR shooters prefer to manually focus the camera: so a focus gear might also be required.
Closer is Better: Wide-Angle
|Wide-Angle Lenses allows you to get close to your subject for better lighting while allowing you to see the surrounding environment
In order to photograph large marine life, reef scenes, full-length diver portraits and shipwrecks, you need to use an ultra wide-angle lens. You need a lens that is the equivalent of a 20mm lens on a 35mm camera or wider. In the past this was a problem when using digital SLRs. Many DSLR cameras have a chip that is smaller than a piece of film. In order to get the same angle of view on a 35mm camera you multiply your lens focal length by 1.5X. Thus your 20mm lens on a digital SLR would equal the view of a 30mm lens on a film SLR. Lens manufactures are producing shorter lenses made just for digital SLRs called DX lenses. Nikon has a 10.5mm high quality fisheye lens. They also have a 12-24mm zoom lens that many underwater photographers are using. Canon has a 10-22mm zoom that is ideal for underwater. Sigma, Tokina and other 3rd party lens manufacturers are coming out with super wide-angle prime and zoom lenses. Now that full frame cameras are becoming more economical, more of them are being used underwater. Keep in mind that if you are using a full frame camera DX lenses are not compatible.
Housings for digital SLRs do not include a lens port. Housing manufacturers have a variety of ports and you need to select your port to match your lens. A port extension, shade, focus or zoom gear might also be required. When selecting cameras, lenses and housings, make sure the housing supports your preferred lens. Housing manufacturers have lens charts on their websites. The B&H website has a link to the lens chart listed with each housing, letting you see which lenses are supported and which are the proper ports, extensions, shades and gears that are required.
Most digi-cam cameras have built-in lenses that are around the 35mm lens equivalent on a 35mm camera. The chips on these cameras are very small. A lens might have a focal length of only 5.8mm but it will produce an angle of view equal to a 35mm lens. In order to get a wider angle of view, some housings allow you to use an auxiliary wide-angle lens attached to the housing. Some, but not all, Olympus and Ikelite housings have a filter thread on the outside of the lens port. This allows auxiliary lenses with a filter thread to be attached directly to the housing. Some housings need an adapter to use threaded lenses.
Fantasea makes housings for many of the Nikon Coolpix and other small digi-cams. Most of these housings will accept a Fantasea conversion lens. The housings that are made by Canon, Olympus, Sony, Nikon and many other camera manufacturers are not set up for auxiliary lenses. Epoque makes a universal adapter, so auxiliary lenses can be used with these housings. Fantasea makes auxiliary domes for their housings as well as those of other manufactures. These domes are not wide-angle lenses but they correct for the size distortion that happens underwater. Underwater everything appears 25% bigger and closer to both your eye and to your lens. These auxiliary domes bring the angle of view back to what it is on land.
Sea & Sea, and Sealife make underwater cameras. These are small digi-cam land cameras sold in a kit with the housing. Both Sea & Sea and Sealife have their own auxiliary wide-angle lenses that mount onto these housings.
If you are planning to do wide-angle photography with a digi-cam, it is important to make sure the camera and housing combination you choose allows you to use some sort of auxiliary lens or dome. Budget is always a consideration; the prices of these lenses vary from $99 up to $400 or more. Of course, you get what you pay for.
Keeping Color Natural: White Balance and Filters
|Using available light and letting the subject go blue in salt water could be a nice effect
As you go deeper underwater you start to lose color. Both film and digital chips are more sensitive to this than your eyes. In warm water the color will go blue. In cold northern salt water and fresh water, your images will go green because of the algae. In 60' or shallower water you can use a filter to bring back some of the color. With digital cameras, you can change the white balance of your chip. In effect, this is putting an electronic filter on your camera. Some cameras have underwater white balance presets. The setting is for blue water only. To use this feature, you would go to white balance or scene mode in the menu and pick the 'underwater' icon-usually represented as a fish.
For cameras that don't have an underwater preset you can do a custom white balance. Use a white slate and follow the directions on your camera to do a custom light balance just like you would do on land. For best results, do the white balance at the same depth you are planning on shooting at.
An alternative to white balance is to use a filter made to correct for underwater color. Fantasea, Epoque, and Ikelite make warm and cold water filters for many of their housings. Manufacturers of underwater video housings such as Equinox and Amphipico make both cold and warm water filters in a variety of sizes. These filters can be adapted for still cameras as well.
Whenever you are using a filter or underwater white balance, it is important that all flash or other artificial light is turned off. These filters are for available light only. For some subjects like shipwrecks, just shooting available light and letting the color go green or blue could be a nice effect.
Artificial Light: Strobes
The best way to correct for the lack of natural color underwater is to bring an artificial light source close enough to your subject to bring the color back. For still photography the most common way to do this is to use flash. Not only does electronic flash have the same color light as the sun, it also freezes action. The small built–in flash on most digi-cam and SLR cameras have limited use underwater. The main problem with the built–in flash is that it is usually positioned directly over the lens. No matter how clear the water looks, there are always particles in the water. When the flash is over the lens, the angle of the light will illuminate all the particles and they will bounce the light right back. This creates a white spot effect in your images called "backscatter".
If you are very close, and if the water is really clear, and if you do not stir up the bottom, you might get a good photo with the built in flash. A diffuser in front of the flash will help a little. But the best thing to do is to use an off camera flash. You will also need a tray and arm to position and hold the flash to your camera and some way to fire the flash. Underwater strobes (electronic flash) come in prices ranging from $175 to $1000 or more. Remember photography is the art of creating an image with light so buy the best strobe you can afford. Companies such as Sea & Sea , Sealife, Epoque, Fantasea, Bonica, and Ikelite manufacture strobes for a variety of budgets.
When buying a strobe there are many features that need to be considered. First of all, is the flash digital compatible? Many digital cameras use a pre-flash to get exposure information. Older strobes will not work with these cameras. Most digital SLR's do not use a pre-flash when connected by a sync cord. Older strobes should work but only in manual exposure mode. Most digi-cams will need a pre-flash compatible strobe.
Sync Cords and Optical Slave Triggers
Next, how do you fire the strobe? All SLR camera housings as well as some advanced digi-cam housings allow use of sync cords. A sync cord is a hard wired device that connects the flash to the camera. Usually, there is a wire inside the housing. This wire attaches to the cameras hot shoe on one end. The other end is attached to a bulkhead on the housing. The bulkhead sticks outside the housing on the other side allowing a waterproof seal attachment for a sync cord. The other end of the sync has a waterproof seal that attaches on to the strobe.
This can get very confusing. Many housing companies use a Nikonos style 5-pin sync connection. Ikelite has a connection that is only for Ikelite housing. Also, every strobe manufacturer uses a different connection on their strobe. So if you are using an Ikelite housing with an Ikelite strobe, you need a sync cord that has an Ikelite connection on both sides. If you are using a Sea & Sea housing with a Sea & Sea strobe, you can get a Sea & Sea Sync cord that will have a Sea & Sea strobe connector on one end and a Nikonos connector on the other for the housing.
Ikelite makes many different sync cords. Thus if you are using an Ikelite strobe with an Aquatica housing, you can get an Ikelite sync cord that has the Ikelite connector on one side for the strobe and the Nikonos connector on the other side for the housing. Again before buying the camera, housing and strobe, it is best to do your research on what will work.
If your camera and strobe combination allows TTL (Through the Lens) exposure control you have to make sure you have the correct sync cord so the camera and strobe can communicate to each other. Ikelite supports TTL with their SLR housings when using Ikelite strobes. Sea & Sea also supports TTL when using Sea & Sea housings and strobes, but the correct TTL converter has to be used.
Most digi-cams do not have hot shoes so there is no place to make a connection with a sync cord. For these cameras, you need an optical slave trigger to fire the strobe. The way this works is, when the built-in flash fires, the light triggers the off camera flash. Some strobes have built-in slaves while others require a separate slave. Again, it is important to make sure the strobe and the slave are pre-flash compatible if the camera uses a pre-flash. To make this light trigger more efficient, some strobes use a fiber optic cable. This cable attaches to the housing over the built-in flash and connects on the other end to the slave trigger of the flash. The light travels up the cable and triggers the off-camera flash. Another advantage of this cable is that it covers the built-in flash and helps prevent "backscatter". In selecting a strobe, it is important to see if the strobe has or allows a slave trigger to be used. Some strobes have a slave trigger only and do not allow use of a sync cord. This might be okay for your digi-cam but remember, if and when you upgrade to an SLR you might need a new strobe. Many SLR housings now have dual ports for plugging in fiber optic cables as well as a bulkhead for sync cords.
TTL, Manual Exposure and Other Strobe Features
|The shutter speed of the camera was set to underexpose the background to make it a dark blue while the f / stop was set for proper exposure for the turtle and diver
When purchasing a strobe, you also need to consider exposure control. Manual control requires the most skill but gives you the most control. When you shoot underwater, you want to use the shutter speed to control the lightness or darkness of the background. Then use the aperture to get proper exposure on the main subject. Of course this requires that the camera allows you to control the shutter speed and aperture (f/stop). Some strobes have a dial which allows you to dial the intensity of the light higher or lower. This is a very useful feature. For digi-cams that have "Auto" only, proper exposure can be dialed in on the strobe. Ikelite makes a manual controller. This is a slave that allows you to dial the strobe power up or down. This is an additional piece of equipment. Sea & Sea strobes and more economical strobes by Bonica and Sealife have a built-in controller.
Automatic exposure is done in one of two ways. Auto strobes have a sensor mounted in front of the strobe. This sensor determines when the appropriate amount of light has been provided by the strobe. The sensor picks up light reflected by the subject area and extinguishes strobe output when it calculates a correct exposure for a certain f/stop. Fanatsea and Bonica have strobes that work this way. These strobes do not talk to the camera so they will work with many different cameras.
Through-The-Lens (TTL) exposure control, the sensor is inside the camera. This sensor determines when the appropriate amount of light has been provided by the strobe. The sensor picks up light reflected by the subject area and extinguishes strobe output when it calculates a correct exposure. Since the sensor is placed where the light enters the camera, it is more accurate. It is also more complicated since the camera and strobes have to talk to each other.
|The shutter speed of the camera was set to properly expose the background to make it a pleasing blue while the f / stop was set for proper exposure for the diver and wreck
Another consideration when buying a strobe is the angle the light will cover. If you are shooting with wide-angle lenses, you need a strobe that will cover a large area. Using two strobes will help cover a large area and you have more creative lighting options. Some high-end strobes have a built-in aiming light. This is a small, continuous light that helps you point the light correctly. Since everything underwater looks 25% closer, many new photographers point the strobe in front of the subject instead of at it. Built–in aiming lights help prevent this from happening. It also makes your strobe into a dive light for night dives.
Make sure you have a strobe arm that is flexible enough to easily position the strobe where you want it. The best arms are two or more sections attached to each other with a ball clamp. These are called ball joint arms. Another good arm type is made of small sections attached to each other that can individually be moved. This is called a flexible arm.
For wide-angle photography, you will want long 16 to 20" arms in order to move the lights far to the side to avoid "backscatter"; it is best to use 2 lights for even lighting. The same arms can be used for macro photography, but 8 to 12" arms are adequate. Two strobes can create some interesting lighting effects but one strobe is adequate for macro.
Some photographers like to use continuous video lights instead of flash. When using these lights you have less control in balancing out the ratio of available-to-artificial light, but they can be easier to use. Cameras can be set on automatic & you can just shoot. Continuous light is also good in overhead environments such as inside shipwrecks and caves. When using continuous light, the photographer does not have the extra task load of handling a separate light for vision and a strobe for imaging.
|In overhead environments such as caves, continuous lighting is easier and can be safer. Remember that photography adds more task loading and should only be done in an environment that you are already comfortable in. Safety always comes first.
Even when shooting with flash, using a continuous light as a focus light can be very useful. Today’s cameras all use an auto focus system that requires a certain amount of light and contrast. A good focus light will allow the camera to focus faster and more efficiently. Many housings have an accessory shoe over the viewfinder. This is a perfect place to mount a focus light.
Warranty and Insurance
Most cameras and strobes come with a minimum of a one year manufacturer's warranty protecting against manufacturer's defects. They will not cover the camera inside the housing; often manufacturers will claim that a flood was caused by user error and most of the time it is. Diver Equipment Protection Plan (DEPP) (www.awryinc.com) and Divers Alert Network (DAN) (www.diversalertnetwork.org) offer dive equipment insurance. They will insure camera gear against flooding as well. Fantasea includes one year of DEPP flood insurance with all of their camera housings. This will insure the camera even if the flood was caused by user error.
In order to avoid flooding it is important to perform proper pre and post dive maintenance. Before the dive, it is important to check your o-rings for dirt and damage. Clean away any dirt and replace even slightly damaged o-rings. It is a good idea to carry with you a complete extra set of o-rings on each trip. Imagine spending thousands of dollars on a trip and not being able to take underwater photos because of a damaged $15 o-ring. Don't forget the o-rings on your strobes and all connectors. If the o-rings require grease make sure it is done properly. You want just enough grease to make the o-ring feel slippery. Then check the o-ring again to make sure there is no dirt.
Don't forget about your non-user-replacement o-rings. Check the instructions for how often the gear should be sent back to the manufacturer for maintenance. An o-ring seal, seals every button. These o-rings also get worn out and rotted away by salt water and need to be replaced by the manufacturer every year or two.
Post dive maintenance requires rinsing the gear off to remove the salt water. After surfacing from a dive, give the gear a quick rinse on the boat and then rinse it thoroughly back at the dock. If you cannot rinse the gear on the boat, it is better to keep it wet until you can give it a good wash. Carrying a bucket that you can fill with water (even salt water) to keep your gear wet is a good idea. This will prevent salt water from drying and leaving damaging salt crystals on your equipment.
Time to Get Wet
Photography does add a new dimension to your diving experience but it also adds task loading. Make sure your dive skills are automatic. Your safety comes first. Also make sure you are not hurting the reef you are documenting. The ability to hover over your subject and still be able to use your camera is critical, in order not to destroy the environment that you love.
|Underwater digital photography is easy and fun. Hit the water and keep on shooting
Once you put your underwater digital imaging system together it is time to get wet! Underwater digital photography is easy and fun. Even when you make mistakes you will not be wasting money on film. So experiment and keep shooting. The more you shoot, the better you will get. Soon, you will have a portfolio of underwater images to print or e-mail to all your dive buddies and non-diving friends.
Larry Cohen has worked as a studio and location photographer since the late 70's. His clients included Baccarat Crystal, Fuji, Kodak, Sony, General Electric, Time Warner and others. His underwater photos have appeared in such publications as Sport Diver, Immersed Magazine, Sub Aqua Journal, Alert Diver and Northeast Dive News. His photos have also appeared in books such as National Audubon Society Field Guide to Tropical Marine Fishes. In order to extend bottom time and to get closer to marine life he now dives with a Closed Circuit Rebreather. Larry is a founding member of the New York Underwater Photo Society. He is the current president of The NYC Sea Gypsies dive club and is on the executive committee of Oceanblue Divers dive club in Manhattan. At B&H Photo, Larry is a technical writer.
Visit Larry's site at www.liquidimagesuw.com