Underwater Digital Compact Photography   

Introduction to Digital Compact Underwater Photography

The last few years have witnessed nothing short of a
revolution in entry level underwater photography. The arrival of low cost digital cameras and housings has made quality underwater imaging available to almost all divers. For the first time budget underwater camera systems are available that are versatile enough to tackle subjects that used to be the exclusive domain of professional SLR camera owners. As with any aspect of photographic equipment, a certain amount of care is needed to ensure that you get the equipment you really need. This section of our web site is designed to guide you through getting started on your research into choosing your first underwater digital camera.


 

Key benefits of digital cameras are...

Real Image Viewing - The LCD monitor on the camera back lets you see your subject exactly as it will be framed on your photograph. This does away with one of the biggest disadvantages associated with entry level film cameras: the separate viewfinder. Separate viewfinders see, as the term suggests, a separate image to the lens. Overcoming this to get accurately framed images requires practice. Often heads or tails are cut off, or part of the picture is excluded or stuff you didn't want in the shot strays in. The LCD monitor avoids these problems altogether.

Instant Playback - The LCD monitor also lets you see the picture you have just taken seconds after you took it. This instant feedback lets you confirm that you got the picture first time or spurs you on to try again. The instant playback also puts you on a fast track learning curve. You will quickly discover what works and what doesn't. You can see the effect instantly in the water.

Versatile Lenses - Digital cameras usually have zoom lenses built in. The zoom affords you the flexibility to frame shots the way you want and to zoom in on shy subjects. Keeping your distance from easily spooked critters makes it much easier to capture them on card. The close up or macro facility that is also built into most digital cameras allows you to shoot very small subjects like cup corals or clown fish easily.

Autofocus is as reliable underwater as it is in air. It usually allows you to shoot subjects at any distance from a few centimetres away to infinity. If a subject moves away or towards you the autofocus can normally track it.

Advanced Technology - Taking advantage of the volume marketplace has enabled digital camera manufacturers to increase specifications while actually reducing prices to the consumer. So many digital cameras offer a choice of exposure modes, such as program for getting started, alongside shutter or aperture priority or full manual for those who wish to take more control. We recommend only those digital compact cameras that let you choose the aperture yourself. This is vital for working with strobes. This is one reason that we actually argue against buying the vast majority of the camera and housing combinations usually on offer. You'll often get exposure compensation for overcoming tricky lighting conditions and a choice of flash modes including slow sync for introducing movement to your images.

Colour Balance Control - You can usually alter white balance to help avoid colour loss underwater and some cameras have built in electronic filters for underwater use that can also help you get more pleasing tones without using a flash gun.

Control of the Final Image - Shooting prints has normally placed the photographer at the mercy of the developing and printing lab. Some are very good indeed. Others are not. The colour cast in underwater shots often seems to confuse automatic printers and the final results can be lacklustre. Digital photographers can control the look of their images by using software such as Photoshop. Using simple programs you can alter the brightness and contrast of your images, enhance or change colours, remove or add subject matter and crop to your personal taste. They can also print their own pictures inexpensively.

Low Shooting Costs - Digital is a very low cost way to shoot underwater pictures. Storage media, unlike film, can be used over and over again. It costs only electricity to view your results on your computer. You also have almost unlimited shots per dive. You can literally take hundreds of pictures on a single card. With film you are typically limited to 36 frames. If you want more pictures you need to take additional cameras down with you. With so few shots available, film photographers had to think very carefully about taking creative risks. The digital photographer has no such concerns. You can try for a shot that might not work out and simply delete it if it fails. But equally you might end up with a truly excellent image.


Canon IXUS 960IS, 12.1MP, with Inon Fisheye UFL 165AD Lens

Building a System for Effective Underwater Digital Photography

Digital users can choose from a rapidly expanding range of accessories. These include flashunits, strobe arms, filters, macro, wide angle and even super wide fisheye lenses. Before plunging ahead and investing heavily in accessories it is important to think through whether they actually offer significant benefits for the kind of photography you want to do.

Over the next few sections we'll provide a guide to some of the equipment available and its applications.....

Do You Need A Flashgun? - No, Yes and Maybe..... Strobes offer three main advantages for underwater photography. Strobes can illuminate dark places. They can restore "true" colours. They can be used to light creatively. For night dives, for instance, a strobe simply provides illumination as it would on land at night. Restoring true colours is a little different. Colour, even when illuminated by the sun, is lost very quickly as you descend through water. Even the most powerful underwater flashgun cannot begin to compare with the sunlight. So the distance that you'll get good colours over is very short - about 1.5 metres at best. This also assumes you can use a wide aperture on your camera - one reason we don't recommend program or auto cameras is you cannot control this all important setting. Flash guns are also used to "aim" light to create shadows and textures for a more pleasing image. You don't automatically need to buy a separate flashgun or strobe. Built in guns work very well for close up pictures, even in poor visibility. In clear conditions you can shoot over longer distances without incurring the dreaded backscatter. Built in guns have their advantages. The light is always aimed at your subject, exposure is automatic and there is no additional bulk and drag. Separate flashguns are needed in low visibility conditions. To avoid backscatter (light reflecting off debris between the light source and the subject) you have to move the light source off the camera. Typically you'll want to get the strobe 30 cm to 45 cm off the camera. "Bolt on" strobes provide a little additional power, but do nothing to help reduce backscatter. Separate flashguns may also be essential with some add on lenses that can obscure the built in strobe. For extreme close ups off camera flash may also be needed to light your subject evenly. Built in flashguns provide only one kind of light - full frontal. If you want to light your subject creatively to enhance textures or create a mood, then an off camera flash will let you do this.


Flash has been used to lift the images
of the fish in the foreground .

Strobe or Video Light?

Typically commercial divers have to work in very poor visibility. Also, it's the nature of the commercial diving world that divers are often presented with equipment with which they are unfamiliar and told to "dive it". It's also likely that the equipment will be mistreated. We usually supply commercial operators with video lights. They need little maintenance, require the minimum of assembly, as they are cable free and, in the rugged environment of working diving, have fewer failure points than a strobe system. The downside is that a videolight that provides sufficient light for general photography (around 50 watts or so) for a reasonable length of time (say fifty minutes) will be heavy and bulky. This can make them a pain to travel with. Lights that are heavy in the water also require quality arms to properly support them - which are expensive. Video lights will also need to be recharged regularly, perhaps even between dives, and this will usually take a minimum of three hours. Many lights take much longer. If you make multiple dives this becomes a major consideration. On balance we believe that most underwater digital photographers are better served by using underwater flashunits, rather than videolights.

Choosing a flash unit - Digital stills cameras don't automatically operate well with all flashunits. If you already own an underwater film camera then it is quite likely your existing strobe won't work well (or at all) with a digital camera. Digital cameras present two problems for flashgun designers. Firstly, they don't measure the light in the same way as film cameras. That has meant going back to the drawing board for underwater flashgun manufacturers. Digital cameras put out a series of pre flashes to determine correct exposure. Many digital cameras and housings cannot easily be wired to an underwater strobe. So the strobes have to be fired by a slave. The light from the cameras own strobe triggers the underwater gun. With film cameras it is relatively simple to slave a strobe. The triggering strobe fires once and the slave fires with it. With pre flashes it is more complicated. The slave gun has to fire at the right time. So it has to fire in sync with the final flash from the built in gun. Complicating things further, the number of preflashes isn't standardised. To get over this, some guns are designed with high speed recycling - they simply fire with all the preflashes and the main flash. Others offer a programmable feature that can be set to ignore preflashes. Another issue is putting the right amount of light on to your subject. This is less of an issue with film cameras because print film is easily manipulated and corrected at the processing stage. So for entry level film cameras a simple flashunit with just one power setting is usually adequate. Digital cameras require much more accurately controlled lighting. There are four principle methods of getting the right exposure with off camera strobes. It is important to understand the differences and to thoroughly check the small print to confirm the strobe you are considering really does operate the way you think it does. At the moment we feel that some manufacturers and suppliers are creating confusion by claiming greater degrees of automation than their guns strictly provide. It also does not help that the industry has not standardised terms to describe how strobes work and what they can and cannot do.

How Digital Strobes Work

Manual Strobes - Manual flash units do not provide automatic exposure. If you use a gun designed for a film camera, and can get it to sync with your camera, you may be able to get good exposures. However it takes experience and skill. Usually a strobe designed for a film camera has only got one to three power settings. This does not give you a lot of discretion for shooting at different distances or for adjusting for different shades and reflectivity. A manual strobe for digital cameras will usually have six or more power settings. Like the dimmer on a light switch, having so many choices gives you lots of scope for lighting all sorts of subjects over a range of distances, from supermacro to distance shots. To shoot with a manual gun, you take a picture, review it and then adjust the power of the gun until you have the exposure you like best. With a little bit of practice it becomes much less hit or miss than it sounds! You'll probably get the exposure right first time more often than not. However it is a problem with moving subjects that keep varying their distance, because you have to change the power settings in time to their actions.


Colours are quickly lost underwater. Both depth and distance
to your subject diminish colours

Auto Strobes - Auto guns use a sensor built into the strobe or attached via a cable that measure the amount of light that the strobe puts out and quenches it when the subject has received enough light. Auto strobes were used on film cameras until the early eighties, but were not overly popular. They have only been recently reintroduced for digital users. Auto sensors have some limitations. You have to work with your camera set to a specific aperture. Most digital compacts that can be housed do not have this option, making them unsuitable for use with auto guns. If you change the aperture setting you must remember to change the aperture setting on the gun as well so both match. There may be limitations on the apertures you can use and on the film speeds you can select. These may not be the best settings for your water conditions and subjects. The sensor can also be fooled by being poorly placed. For example turning the gun inwards to light a diver's face who is slightly off to one side, while the sensors is pointing directly out into mid water. In this case it may not "see" the main subject and deliver a poor exposure. Backscatter can also fool sensors and create inaccurately exposed pictures.


30 metres down, light from an Inon D-2000 strobe lights both diver-
but only because a wide angle lens allowed the photographer to be
only 1.5 metres from his subject

TTL (Through The Lens) - Our definition of a TTL or camera controlled flash is a system where the camera's own internal flash is used to control the exposure of the slaved gun. To do this a fibre optic cable is usually placed in front of the camera's own flashunit. When you take a picture the internal gun fires and triggers the external gun like an ordinary slave. The camera sees a burst of light and assumes it came from it is own gun. When the camera determines that the subject has been properly lit, it turns off the built in gun. This in turn shuts off the external gun, ensuring a properly exposed flash picture that is fuss free and consistent. Because the sensor that controls the flashgun is built into the camera you cannot miss aim it. It is also less prone to being affected by backscatter as it is not normally in line with the strobe. A further benefit is that if your camera has a flash compensation feature, this will also control the external strobe as well. This can be useful as it allows you to customise the exposure to your taste. For example if you photograph divers it is quite common for the auto exposure to be fooled by dark equipment on their bodies. This causes the automatic exposure to boost the flash power to compensate. The result is that the diver's face is often greatly overexposed. By setting the flash compensation exposure to underexpose a little, this problem is solved. If your camera does not have this feature you'll find it provided on some underwater guns. These are normally just selected on a dial and can be faster to use than a menu based selector.
Since the external gun is controlled directly by the camera's own built in gun, adjustments made to the camera are automatically relayed to the strobe. If you alter the aperture or film speed there is no need to make any additional adjustments to the strobe. So there is almost no scope for making an error by being forgetful or narced. Camera controlled flash is our recommended solution for working with currently available consumer camera and housing combinations represented by Fuji, Olympus, Sony, Canon and similar own label suppliers.


For scenics, a wide angle lens is essential

D-TTL - D-TTL are the most sophisticated flash control systems available to digital underwater photographers. They are most commonly used with digital SLR cameras. These camera and housing combinations let you hardwire your flashgun straight into the camera's own hot shoe. The camera's through the lens (TTL) meter controls the exposure from the strobe. This is a highly dependable and accurate method of both firing your strobe and getting perfect flash exposures. Because metering is through a sensor mounted behind the camera lens it is unaffected by the field of view of the taking lens and it always sees the main subject. Because the flashgun is wired directly into the camera, rather than working as a slave, camera manufacturers expressly warn against using strobes supplied by other makers. Doing so will almost certainly void your warranties. Similar reservations were expressed when independently manufactured strobes were made available for the Nikonos range and when 35 mm SLR owners used unofficial strobes with their housings. Time will tell if these concerns are justified.

Masters and Slaves - Slave is a term you'll commonly hear bandied about by underwater photographers. It refers to any additional flashgun that is triggered by the burst of light from another gun (the master, which is connected to the camera). Slaves are often used to light creatively. For example you can hide a gun behind your subject for rim lighting, or you can give a slave to a diver who is modeling for you to make it look like they are holding a powerful torch. Cave photographers often attach rear facing slaves to other divers in order to light cave passages behind them and add depth to their images.

One Strobe Or Two? - If you are just getting into off-camera strobe photography, we always recommend that you work with just one gun. Two guns add bulk and cost and usually require more skill to shoot successfully. Basically, if you are new to underwater photography, two strobes are probably more trouble than they are worth. Two guns are useful when working with extreme wide angle lenses in dark conditions, such as inside a cave. This is because a single strobe usually does not have enough spread to cover lenses wider than a hundred degrees. In this case the second strobe is used to simply provide additional spread to avoid hot spotting and dark corners. In bright open conditions it is often perfectly viable to light even a superwide lens with a single gun. Any fall off at the edges tends to blend with the sunlight and looks quite natural. For creative lighting using a pair of guns can let you light from two angles to create or reduce shadows or to use back or rim lighting. Getting creative with your lighting angles can lift a picture by providing much greater impact. Finally, many top underwater photographers swear by one or two strobes and won't be swayed in their opinions. So there is no cut and dried answer as to how many you should use.


Sand and other partciles create backscatte-the dots you see in
underwater images. Keeping the strobe high above the camera
helps eliminate or minimise the effect

Strobe Arms - Often overlooked and undervalued, strobe arms deserve some careful consideration. Basic strobe arms are often supplied with strobe packages to keep the purchase price low. Typically they place the gun to one side of the camera lens and slightly above it. This works fairly well in clear water, but will create backscatter in turbid conditions. This fixed position provides little benefit over using the built in gun for shooting with the standard lens or close up accessories. If you use wide angle lenses in clear water it does work quite well in our experience. Built in guns do not usually work satisfactorily with wide angle lenses as the coverage is not matched and often the lens obscures part of the flash. Both scenarios lead to dark patches in the final picture. If you want more flexibility to light your subjects you can either hand-hold your strobe or use a more versatile flashgun arm. Some basic arms cannot be updated and you'll need to buy a new arm altogether. Others are designed to accept extension sections and clamps, allowing you to build on your system at relatively low cost as and when you feel your photography requires it.

Wide Angle - Wide angle lenses serve three main purposes. They let you shoot large subjects, operate in low visibility and manipulate perspective. Water has two main effects on underwater photography. It isn't really clear. Even crystal clear water only equates to a foggy day topside. The debris in the water column physically obscures your subject, making it look soft or out of focus. The more water you have between your camera and the subject, the worse the picture looks. To keep the picture sharp, you need to get as close as possible to your subject. By reducing the water column between your camera and your subject, you also reduce the amount of detritus you have to shoot through. With large subjects like whale sharks and wrecks, a wide angle lens is essential for good photography.


This wreck had to be photographed using an add-on fisheye lens-
an extreme wide angle. The Rozie, off Comino, is simply to big
to shoot with the camera's built in lens

The second effect of shooting through water is that it quickly absorbs colour. You'll only get bright reds, for example, in shallow water over short camera to subject distances. To counter this flashguns are often used. However flash has a limited range through water. So getting close, even with flash or video lights is also vital to capturing vibrant images. Wide angle lenses let you get close enough to large subjects, like other divers, to get good colours. In low visibility, wide angles become vital for anything other than macro and close up photography. In the typical conditions found in the UK, you might have to photograph large subjects like your buddy from under a metre away. Wide angles let you do this.

Wide angle lenses also let you play with perspective. Close focus, wide angle, is an example of this. By placing a smallish subject in the foreground a few inches in front of the lens you can make it tower over a diver just a little further away. Half are also possible with some set ups.


This shot was taken using a Fuji F30 equipped with both an Inon
fisheye lens and an D-2000 strobe. The rich colours are made possible
by staying within 1.5 metres of the model and using a wide aperture

For consumer cameras, wet lenses are readily available. These either screw directly into the housing or mount via an adapter. They can be fitted and removed underwater in a matter of seconds, providing great flexibility. Holders let you store your lenses safely, usually on your strobe arm. Wet lenses can sometimes be used in air. Typically they cover 85 to 100 degrees - roughly equivalent to a Nikonos 20 mm or 15 mm lens. The exact coverage will depend upon your camera's own lens. Prosumer SLR cameras use normal land lenses placed behind special ports attached to the housing. You need to choose your lens before the dive.

Macro Lenses - Most consumer digital cameras have a macro or extreme close up facility built in. This lets you photograph tiny subjects such as nudibranchs and porcelain crabs. However there may be limits on how close you can really shoot underwater because of flashgun limitations. Some cameras don't permit the use of flash at very near distances because the flash cannot light the whole frame evenly. In this case an off-camera flash will not work because there is no flash from the camera to trigger it. Macro lenses usually attach to your housing via a screw thread or an adapter. They allow you to shoot from further back while still filling the frame. This lets you use your built in flash or an off- camera strobe as you prefer. You can also use much of your zoom range for more control over the final composition. Keeping your distance also helps to avoid damaging coral and can make shy creatures easier to photograph. Prosumer cameras use macro lenses that are designed to provide a continous focusing range from a few centimeters away to infinity. For even higher magnification prosumer camera owners may add teleconverters or close up lenses.


This shot, taken with flash, reveals more of the
diver. But colours are drab because of the
distance to the diver


With the diver much closer, colours are brighter
and flesh tones are accurate


Natural light shots can have impact and are easy to take


Natural light shots can have impact when shot as
sillouhettes. This required the camera settings
to be altered to create underexposure