Underwater Photos with Digital Compacts

Last month, we ran a story by our gear pro, John Bantin, about why he preferred full-frame to compact digital cameras. Undercurrent subscriber and photographer Michael Zagachin (Peabody, MA) wrote us to disagree. “The article may confuse the average vacation diver into thinking that more expensive equipment will make his pictures better. I use a digital compact, with no flash or strobe, and the critters in the photos on my website (www.redberryphoto.com/underwater) came out pretty good. I’d like to address necessary skills and tips for using simple, inexpensive equipment that can produce good underwater images for the amateur underwater photographer.” Here is his piece.

Many divers these days use compact digital cameras underwater, but their images are often poor, whether they have strobes or not. There can be many reasons for that, but the most probable are lack of basic photographic skills and unfamiliarity with the incredible capabilities of their tiny cameras. There are numerous reviews of underwater photo equipment that not all of us can afford, but articles about underwater photography on a budget are rare.

Those superb underwater images you see in dive magazines were not made by equipment but rather by very experienced photographers with years of practice. Like buying a bike from Lance Armstrong will not make you a better cyclist, spending your kids’ inheritance on expensive photo equipment won’t make your pictures better. Even learning a basic understanding of composition and exposure would make wonders to your pictures.

Equipment Essentials

Compact digital cameras offer a unique opportunity for those of us with no aspirations to be published in National Geographic. We can bring home quality images from a dive without exorbitant cost, bulk and hassle. Of course, you need good diving skills to do that, meaning you must comfortably control your position underwater using just your lungs and fins. Hands are for operating your camera.

Select a camera with features such as custom white balance, spot metering, continuous shutter release, auto ISO and macro capability. Also pick the camera with the fastest (f/2.8 at least) and the widest (28mm at least) lens you can get. Canon has recently come out with a terrific digital compact S90 that has an even faster f/2.0 lens with a larger than usual sensor. These two features are very important to the quality of underwater pictures. Other manufacturers will probably follow shortly.

Another important feature is a large LCD; that will be a big help underwater. Ignore the megapixels hype; all cameras have more than enough of them these days.

Getting Colors and Highlights Right

If you need to buy a camera, make sure a housing for it is available. The housing is generally just slightly larger than the camera itself. It should be rated to a depth of 130 feet, dedicated to a specific camera and provide control of each and every camera function. The camera/housing combo needs to be neutrally buoyant. Canon makes a set of small weights that attaches to the tripod socket of the housing to control camera buoyancy.

Image sharpness is the hardest issue to overcome underwater. Everything moves, including the photographer and the camera itself. Setting the camera to aperture priority mode, and setting the aperture to the widest (smallest f/number) will ensure the fastest shutter speed for available light. Combined with the ISO set to Auto, this will help to get the sharpest pictures possible under the present lighting conditions.

Yes, the depth-of-field and noise will be sacrificed to some extent, but it is the out-of-focus images that are deleted first. Most digital compact cameras suffer from shutter lag -- that is the price we pay for their size. However, using the continuous shooting mode dramatically increases the probability of producing a sharp image. Reducing image-display time right after the shot or shutting it off completely will make the camera work a bit faster.

To make things simple, I don’t use strobes, so getting the colors right is a challenge. That’s why the custom white balance is so important. Adjusting the white balance before every shot is critical. Variation in depth even by a few feet will affect the colors. The red part of the spectrum disappears and reappears very quickly with change in depth, turning your whites into ugly pinks or blues. The camera needs to know what white color is at every depth in order to get the rest of the spectrum right. I aim the camera on the palm of my hand to set the white balance every time my next potential “model.” appears. I never use built-in flash; it is nearly useless underwater.

Another challenge is blown highlights. On a sunny day, the difference between light and shadows is tremendous. Spot metering for highlights will produce underexposed images but that can easily be corrected in post-processing, unlike blown highlights.

Another trick is to set the exposure compensation to -2/3. Not being a big fan of sitting at the computer, I keep post-processing to a minimum: adjust levels, add a bit of saturation, contrast, and un-sharp mask. If the image requires a lot of work, I delete it.

Safekeeping is Key

It is a good idea to set as many camera functions as possible before the dive, leaving only a minimum of settings to be adjusted underwater. The display is the biggest power-drainer in compacts. Even though I dive with my camera turned on, I keep the LCD display off until the worthy subject appears.

Once during a dive, I watched with horror as water droplets were collecting into a little pool inside the housing. Luckily the camera survived, but now I keep the housing with the camera out of the sun so condensation doesn’t collect when it cools off underwater. I usually wrap the housing in a towel on the way to the boat, and then keep it in the water bucket most dive boats provide. Soak the housing in fresh water after diving, and push every button several times to flush salt water out of the button o-rings. Maintenance of the housing is minimal and limited to applying just a touch of silicon to a single o-ring.

Now to economics: My digital compact camera and its housing set me back about $400 two years ago, which is about three times what just a housing would cost for my Nikon D300 DSLR. If the housing floods, the DSLR body and the lens will be damaged probably beyond any reasonable repair. If the compact camera gets flooded, it can be replaced for a fraction of its original cost because they drop in price almost daily -- so much so that I am thinking of getting a spare one . . . just in case.