A Guide to Choosing Strobes and Video Lights
The amount of camera equipment available for underwater photography can quickly make a beginner’s head spin. Do we need lights underwater? How do lights improve my photos? Are strobes different from video lights? Should I use one or two strobes? Can I use strobes AND lights?
This article discusses everything you need to know about underwater video lights, strobes, why you need them and how you use them.
Why do We Need Light Underwater?
The vast majority of underwater photos you see are lit using underwater camera lights. Some exceptions might be freediving photos that are very blue in color, shipwrecks that are also a muted blue/green, and mammals like dolphins close to the surface.
We know that we lose light as we descend in the water column, which is why many divers carry a torch (or dive light) to bring out the vibrant colors of the reef at depth. Underwater strobes and video lights serve the same purpose; they bring back the color and contrast lost as we descend.
As underwater photographers, this color helps bring POP and energy to our images, fill in gloomy shadows, and help capture sharp images.
Do You Need a Light or Strobe for Underwater Photography?
No, you do not need a video light or strobe for underwater photography since you can capture photos using only ambient light. Using a strobe or light, however, will add vivid color and contrast into close subjects, which is why most avid photographers use them.
Why You Need Lighting Underwater
Underwater Strobe Basics
Underwater strobes, also known as flashes, produce extremely powerful bursts of light that add color and contrast to our underwater photos. This is why most divers carry a torch in order to illuminate the reef with bright color. Strobes are just much effective in producing the bright, even lighting we like for photography.
In addition, the fast flash of our strobes helps freeze the motion of our subject, which is why underwater photographers prefer strobes instead of video lights for still photos. We’ll dive into these differences later in the tutorial.
Strobes are used exclusively for still photos. Sorry video shooters!
How do Strobes Work?
Strobes are specifically designed to work with your underwater camera and housing. The camera will trigger the strobe via electric signal or optical flash when you press the shutter. The strobe fires when it receives this signal.
In between camera and strobe you need to relay the signal.
Fiber Optic Cables
The most common method to trigger the strobe is through a fiber optic cable that relays the light from the camera’s flash to the strobe input. When the camera flash fires, the strobe detects the light via the fiber optic cable and triggers the flash.
Fiber optic cables are great because they’re light, require minimal maintenance, and can even be added and removed underwater.
DSLR and Mirrorless cameras often use a flash trigger, or TTL converter, which turns the camera’s electric signal into an optical flash that can pass through the fiber optic cable. These triggers allow cameras without a built-in popup flash to use fiber optic cables. They also allow cameras that do have a popup flash to circumvent the flash, which saves camera batteries and results in quicker continuous shooting.
Sync cords have been a staple of underwater photography, however are phasing out as fiber optic cables and flash triggers become standard with most housing manufacturers.
While they are very reliable and popular with Ikelite housings and strobes, they require more setup and maintenance time. Each end is attached via o-ring sealed connection, which increases risk of flooding.
Manual vs. TTL (Automatic) Strobe Power
Most underwater cameras allow divers to shoot strobes using automatic power measuring (a process called TTL), but many advanced shooters prefer to control their strobes manually.
This trend is clearly reflected when you look at my 2021 Strobe Comparison and see that the two most affordable strobes offer TTL-only, while all other strobes offer both manual and TTL.
I recommend that all scuba divers who think they’ll stay with the hobby invest in a strobe that does manual and TTL so that you have many years to learn and grow with the strobe.
Underwater Video Light Basics
Video lights are just like regular dive lights, but with specs designed specifically for lighting underwater video. Both dive and video lights are regarded as constant light and require much different basic camera settings than if you were using a strobe.
Your dive light probably has a narrow spot beam, which travels further through the water and is great for inspecting shadows, lighting little caverns, and signaling your dive buddy.
An underwater video light, on the other hand, has a wide beam angle (110-130 degrees), that helps evenly light a wide scene in front of you. This is essential for photo and video shooters, but divers might notice they don’t reach as far and often create more backscatter/haze during night dives in low visibility conditions.
Video lights are versatile tools. They can be used for shooting video (of course!), as a focus light for macro still photos, and even for general still photo lighting.
Can You Use a Video Light & Strobe at the Same Time?
Generally you will not use a strobe and underwater video light at the same time. This is because you use different settings for wide-angle and macro shooting with strobes than you would with video lights.
Underwater strobes produce significantly brighter light than video lights, so in the exact same dive conditions, your camera settings will be set to let less light enter the camera when using strobes.
In my Virtual Photo Lessons I break these into Strobe Settings (for macro and wide-angle) and Constant Light Settings (ambient light and still photos using video lights). Learn more in this webinar I hosted for Atlantis Philippines on YouTube: Underwater Photo Tips for Diving the Philippines.
One important note is that you should use a macro focus light to help your camera achieve proper autofocus when using a strobe or two. With the proper settings, the light from the focus light will be overpowered by the strobe(s) and not appear in the image.
One last note is that there are many exception for advanced shooters, primarily for macro images. We’ll leave that for the advanced lessons!
Which is Best: Strobe or Video Light?
The choice between a strobe and a video light is a tough one, and really depends on what you plan to be shooting. Let’s break it down by type of shooter.
On a Tight Budget
This shooter likely has a compact housing and is looking for the most affordable way to add underwater lighting. Remember, not only do you need to purchase the light, but you need a tray with handle for your housing, as well as an arm to hold and position the light (explained below).
I recommend a video light between 1,000 and 2,500 lumens. This setup will do well for macro photo and video, and even allow you to light some carefully composed wide-angle scenes. It won’t deliver the same results as a strobe, but compensates by being versatile.
The nice thing is that if you start really practicing underwater photo and video, and want to invest in a more advanced system, this light stays with you as a macro focus light. A good investment!
Entry Level Setup
This diver wants to shoot nice photos on a budget and also might experiment with some video.
I recommend a strobe AND a video light for this setup. The level of each will come down to budget. While I’m very conservative on recommending advanced cameras, I do say that investing in your lighting is a smart move, as you can grow with the gear for as long as it lasts.
The strobe will help you capture crisp still photos – both macro and wide-angle. The video light will serve as a macro focus light (still photos) and as a video light for the occasional clip.
This diver is serious about underwater photography.
I recommend two strobes AND a video light. Dual strobes take wide-angle photography to the next level while really helping to minimize backscatter in your images. As before, the video light works both as a macro focus light and as a video light if desired.
This diver lives for the motion of clips. Dual video lights give wide-angle video more lighting, which is essential for reefs, big animals, and divers, where the shadows and backscatter from a single light can prove troublesome.
Dual lights also increase the light coverage area, allow key light and fill light effects, backlighting and much more.
Advanced Ready for Everything
Our last diver has the cash and the desire to shoot both photo and video – sometimes even on the same dive! This setup will require both dual strobes AND dual video lights.
How do you Attach Strobes and Lights to the Housing?
Underwater strobes and video lights are both mounted to arms that mount to the top of a handle and tray system that attaches to your housing. Phew! The handles help you keep the housing stable while improving ergonomics and ease of use.
There are two general system available. The first is an arm and clamp type system. The second is a loc-line / flex-connect system. We’ll discuss both.
Arm and Clamp System
Arms and clamps the most widely used system for attaching underwater video lights and strobes to a housing. All underwater housing and tray kits include (or use as an add-on) a 1-inch / 25mm ball end adapter, making this a very universal system across all camera systems.
Each aluminum arm is available in various lengths and has a 1-inch (25mm) ball end on either side. Some of the arms even have hollow plastic tubes that create lift underwater (trapped air). When added to a heavy camera system, the float arms serve to help make the entire camera system neutrally buoyant underwater.
Multiple arms are connected using a twist clamp that holds the two ball ends together. You can tighten down the clamps to clock the arms in position at the desired angle, or loosen them in order to reposition.
Watch the video below to learn how to find the ‘sweet spot’ that allows you to reposition your lights and strobes without adjusting the clamp every time.
3 Basic Tips for Using Strobe Arms and Clamps
Flex-Connect & Loc-Line Systems
These systems are much lighter, smaller and more affordable, making them a great choice for those interested in a light, low-profile camera rig.
SeaLife’s Sea Dragon Flex-Connect System is perfect for those who want an all-in-one solution for camera + light(s) + strobe(s), or any similar combination. The modular system offers a number of positioning possibilities, while the clever quick disconnect system makes setting up and breaking down the system insanely fast.
I find it a lot of fun to experiment with disconnecting and handholding a light for creative shots when using the Flex-Connect system (since it’s so easy to disconnect/connect).
Loc-Line arms are popular for Underwater GoPro Lights, but not adopted much beyond that. The arms make some noticeable creaks when moving them around, but the compact size and light weight make them another great option for a low-profile camera system.
Best Underwater Strobes
There are many different strobes available at various price points. Some of the key factors to look for are the guide number (brightness of the flash), price, recycle rate for sequential firing, and compatibility with your camera if you plan to shoot in TTL (auto) mode.
Check out my detailed 2020 Underwater Strobe Guide to learn all about the best strobes for your camera.
2021 Underwater Strobe Comparison
Best Underwater Video Lights
Underwater lights can be broken into two categories based on power level (lumens) and intended use.
Focus lights are lower power lights (about 1000 lumens) used by virtually all macro photographers to help the camera achieve focus.
Video lights are generally more powerful with wider beam angles and used for video. Some photographers use their video light for still photos as well.
Check out my detailed 2020 Underwater Video Light Guide to learn about the best focus lights and video lights for your system.
2021 Video Light Comparison
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