Mastering Underwater Photography: Accessories For Strobes

In the last few articles, we have discussed the considerations to make when purchasing your first set of strobes, then how to place our strobes in the correct position followed by learning more advanced techniques. Now that we have mastered the basic use of strobe light it’s time to look at the myriad of strobe accessories that can be used to modify the light output from the strobe.

In essence, there are two types of light we are trying to achieve, either soft, diffused, and even light that is often desirable in wide-angle photography or harsh-edged narrow-beamed light where we control the edges on smaller subjects for macro photography. Almost all strobes are aimed at a softer and even light, and one of the key selling points is usually the width of the beam measured in degrees and how even the light is within that beam. Much of the technology in the top-end strobe such as circular flash tubes is aimed at creating this soft even beam. However, almost all strobe manufacturers now make additional accessories to modify the light, so let’s look at the main ones and discuss why we would use them and how they will affect your photography.

Diffusers

Diffusers are the most commonly used underwater strobe accessory; in fact, almost all strobe users buy a set of strobes and put them on then never take them off without really having any thought for the effect of the diffusers. In essence, a diffuser is usually a dome-shaped cover made of white plastic. The idea behind this is for the light from the strobe to be spread wider, softer, and more evenly across a scene. This can be a great accessory for shooting things such as coral reef scenes where you are looking for edge-to-edge even lighting across the frame. They work especially well on strobes that have a T-shaped flash tube as it helps to avoid the hot spots in the image.

The diffusers now also come in different light temperatures that are aimed at changing slightly the color of the light from the strobe; this then, in turn, changes, for example, greener water to a more blue color of the water column. There are many different color temperatures that you can buy, but usually, they are aimed at ambient light, green water, or blue water photography.

Since I have begun using strobes with circular flash tubes, I actually use my diffusers less than ever as they are not needed as much as before to get an even spread of light. I use them for reef shooting, but often I like to shoot into the sun for example and therefore need to manage the ambient light by using low ISO and a smaller aperture, then I need the additional strobe power to counteract these settings meaning it is better for me to shoot without the diffusers as when adding them it reduces the light output of the strobe. I almost never use them for macro photography.

Beam Restrictors

Beam restrictors are strobe attachments used to narrow the spread of light emitted from strobes They typically are a type of ring that is attached to the strobe face and protrudes out restricting the width of the beam. By narrowing the beam of light, beam restrictors help photographers to precisely control where the light falls and ensure it only falls on the subject and to ensure that there is no extraneous light. This can be particularly useful when shooting macro photography, as it allows for more focused and concentrated lighting, minimizing light spillage and reducing backscatter.

As the scene you are shooting becomes smaller, it is more important to have precise control of the edge of the beam; this is why we use beam restrictors for macro shooting. Also in macro photography one of the most desirable shooting styles is the black background, where only the subject is illuminated and the rest of the image is black separating out the creature from an unsightly background.

Beam restrictors can come in multiple sizes; the Retra beam restrictors for example come in 2 sizes, once you have reached the limits for these then we move on to the next underwater strobe accessory, snoots.

A cheap beam restrictor can be made by cutting up the arms or legs of an old wetsuit. All you need is a cylindrical piece of neoprene about 4” (10 cm) long that you place on the front of your strobe.

Snoots

A snoot is a specialized attachment or device used to create a narrow and focused beam of light from a strobe. Resembling a cone or tube, the snoot is placed over the strobe, effectively restricting the spread of light to a small, targeted area (Spotlight). Most modern snoots come with a way of controlling the size of the spotlight either through an aperture card that slides in and out of the snoot and has different-sized holes within it that are used to make the spotlight larger or smaller or via a dial.

Snoots can be as simple as using a piece of drainpipe attached to the edge of the strobe, but modern snoots now have incorporated glass lens to focus and concentrate the light beam giving a much better light quality output.

Snoot lighting allows you to illuminate specific areas or subjects within their underwater scene with precision, isolating them from the surrounding environment and creating dramatic lighting effects. Snoots are commonly used when photographing small or shy marine creatures, such as macro subjects like nudibranchs or tiny crustaceans, where precise lighting control is essential to highlight intricate details without causing unwanted glare or backscatter. Additionally, snoots can help create artistic effects by selectively lighting certain parts of a scene while leaving others in shadow, adding depth and visual interest to underwater photographs.

Although snooting is mainly aimed at creating a black background in macro photography, snoots are also so much more creative than this and in fact, my favorite ways to use snoots are not in black background images but instead in creative colored background shots. It is not necessary to use snoots if all you are after is a black background, this can usually be achieved with reduction rings and settings and is a lot easier that way.

Of all the light modifiers on the market snoots are the most talked about and most desirable for shooters to master, we will have a special feature piece just on snooting in the near future due to all of the complexities around it.

Remote Strobe Triggers

Remote triggers are often the accessory people know the least about, and is for sure the accessory I see the least in the field. A remote trigger is used to fire a flash that is not on your camera or connected to your camera in any way. Imagine if you were inside a shipwreck and wanted to light a corner of the wreck that is 15 - 30 feet (5 to 10m) away from the camera, or if you wanted to put a light inside a cave scene from distance.

The remote flash trigger is basically a light sensor; it is attached to your remote strobe through a fiber optic cable of any length you need; you then can hide the strobe anywhere in the scene and place the small flash trigger in a place where it is line of sight of your on-camera strobes. When you fire the camera and your on-camera strobes fire, the sensor will see the flash and send its light signal down the fiber optic cable to fire the off-camera strobe.

Usually, I like to carry my off-camera strobe on a little gorilla pod that I have modified to have a ball mount on; this means I can stand the strobe anywhere I want and angle it however I wish within the scene.

When using an off-camera strobe, it’s important to use a quality strobe and not just purchase a cheap low-quality strobe for the task. The off-camera strobe will likely be your main light in the scene and therefore it’s important to use the best quality light. Also when using the off-camera strobes avoid pointing them directly at the camera, it is ok to do so if they are behind an object such as a diver to create backlighting but if the camera can just see the face of the strobe it will create a very ugly and overexposed hotspot on the image.

Conclusion 

Mastering the use of strobe accessories in underwater photography opens up a realm of creative possibilities. Whether it's diffusers for achieving soft, even lighting across wide-angle scenes, beam restrictors for precise control in macro photography, or snoots for spotlighting intricate details, these tools empower you to take your photos to the next level.

While each accessory serves a specific purpose, they also open you up to a whole new host of creative opportunities.