5 Easy Ways to Avoid Backscatter in Underwater Photos
Trying your hand at underwater photography more often than not starts on the edge of a swimming pool. What better way is there to practise your skills than in a safe, sheltered environment? Making the transition into the open ocean, however, can often be a rude awakening. After a seemingly successful dive, you find your beautiful images are suddenly concealed beneath a thick layer of sediment and you can’t quite seem to get rid of it. It’s time to meet your new worst enemy – backscatter. Don’t worry though, this tutorial will look at 5 easy ways to avoid backscatter in underwater photos.
Backscatter is the name given for the illumination of particles in the water between your subject and the camera dome. These particles are the very reason for bad diving visibility, normally during poor weather. When they reflect the light from your strobes, they can create an ugly veil to your photographs and can be frustrating to get rid of in post-production.
The bad news is that there will always be sediment particles in the ocean. It’s an ever-changing and difficult environment to photograph in, with diving conditions being tricky to predict. The good news is that there are plenty of ways to prevent this sediment creating backscatter in your underwater photographs.
#1 The First Rate Frog Kick
To begin with let’s talk about finning. The most natural technique that most recreational divers use is a gentle up and down finning motion. This often creates up and down water propulsion which can stir up an enormous amount of sand and silt from the seabed – reducing visibility and thoroughly annoying your fellow divers. In addition, it’s the easiest way to accidentally damage underwater ecosystems as you pass by without even noticing it.
A far better method that is commonly used by technical divers for its practicality is the frog kick. The frog kick is easily done by bending your knees at a 90-degree angle outwards and gently propelling yourself forward, arcing the legs and bringing them back together with your fins parallel to the seabed. This creates water propulsion to the rear of your body instead of downwards and avoids kicking up unwanted sediment into the water. Less sediment in the water means a minimised chance of backscatter in your photographs. By also creating a more compact shape with your body it becomes easier to carefully manoeuvre yourself around coral whilst using the least amount of energy possible.
#2 Understanding the Culprit
Your strobes are usually to blame for most of the backscatter in underwater photographs. By introducing artificial light, any particles and sediment in the water naturally reflect the light back at you and make it nearly impossible to get a clear photo. Thankfully, there are a few simple tricks that can solve this problem.
By angling your strobes away from your camera, you reduce the amount of light directly hitting the water between your dome port and your subject. You should aim to have just the edge of your light beam brushing against your subject. As a result, your backscatter will most likely disappear completely. Another way to reduce backscatter is to add diffusers to your strobes. These will evenly distribute the light and reduce the harsh reflections you have come to dread. I use an INON white diffuser 2 on each strobe which widens the beam a further 10 degrees.
If using a compact camera be careful of the internal flash firing towards your subject. Even if your external strobes are positioned well the internal flash will still highlight sediment directly in front of your lens. A quick solution for this is to cover the internal flash with a piece of tape. As with most things – duct tape works perfectly well!
#3 Working with the Weather
It isn’t always possible to work with perfect visibility underwater and a good underwater photographer should be prepared to dive safely in a variety of conditions. Poor weather conditions can often give your photographs a moody and emotive feel, although it does mean the issue of backscatter can become far more prominent.
Shooting with ambient light near the surface in these conditions will most likely eliminate the problem. If this isn’t possible, then one way to stop getting backscatter in underwater photographs is to switch to a macro or fisheye lens. By allowing for less space between your subject and your dome port, there are fewer particles in the water likely to reflect light from your strobes. Naturally, your photos will appear sharper, clearer and, with the right strobe position, backscatter free.
#4 Buoyancy and Breathing Control
Neutral buoyancy allows a diver to effectively ‘hover’ at the same depth, and is one of the greatest skills an underwater photographer can have. Although this often comes with experience, being able to control your depth with a simple breath can mean the difference between a dive with 10 metres of visibility and a dive with just 1 metre of visibility.
By keeping off the sea floor, you vastly reduce the amount of sediment in the water and this in turn minimises the amount of backscatter in your photographs. If it’s absolutely necessary to descend to the seabed, try positioning yourself down current from your subject. If you do accidentally stir up the visibility it should drift behind you and not affect your photographs too much.
#5 Develop Post Production Techniques
If the backscatter in your photographs is not too prominent, it may be possible to remove it in post-production. When using Lightroom you can use the spot removal tool to get rid of a few flecks of backscatter. A more thorough edit will need Photoshop’s refined cloning tool to get rid of the small white spots covering your photo.
Another handy tip is to use a little of the ‘de-haze’ tool – this will bring more clarity and contrast to your underwater photos without losing detail. As with all editing – always do it in moderation!
Here are some examples to show the removal of backscatter in post processing:
Hopefully these tips will help you to remove backscatter from your underwater photos. It’s important to ensure you know how to avoid backscatter, as investing so much time and money into performing a dive can be ruined by too many unwanted particles in the water!