Underwater strobe lighting setup for photography

Underwater photography often involves the use of strobes (also known as flashes or flashguns) to illuminate subjects. These strobes are crucial in overcoming the challenges of underwater light absorption and can help produce sharp, vibrant photos with well-defined colors and details. Here's a detailed guide to help you understand how strobes work and how to effectively use them in underwater settings.

Why Are Strobes Important Underwater?

  • Color Absorption: Underwater, light is absorbed progressively based on its wavelength. Reds, oranges, and yellows disappear first, leaving subjects to appear blue or green without supplemental light.
  • Backscatter: If the internal camera flash is used without external strobes, it can cause particles in the water to reflect light back into the camera, creating unwanted backscatter.
  • Sharpness: Without a strobe, slow shutter speeds required for ambient light can result in blurry images, especially for macro shots. A strobe offers the necessary brightness for sharp, high-quality photos.

Understanding How Underwater Strobes Trigger

Modern strobes operate by emitting a flash of light when triggered. When used on manual power, the strobe emits light for a specific duration, depending on the power setting. A higher power setting results in a longer light duration, while a lower setting shortens it. When using TTL (Through the Lens) mode, the strobe performs a pre-flash to determine the appropriate exposure and automatically adjusts the power.

The Impact of Distance on Strobe Light

Strobe light intensity decreases with distance. This principle, called strobe falloff, means that the closer your subject is to the strobe, the more powerful the light will be. For example, moving the subject from around 30 centimeter to around 60 centimeter away reduces the power, while bringing the strobe closer (from around 30 centimeter to around 15 centimeter) increases its power by for example 4 times.

The Difference Between Hard and Soft Light

The quality of light refers to whether the light is hard or soft:

  • Hard Light: Strong, directional light that creates distinct shadows and high contrast. It’s produced by small, intense light sources.
  • Soft Light: Diffuse light coming from various directions, producing gentle shadows and lower contrast. Larger light sources create soft light.

Diffusers are often used to soften hard light by spreading the light out. They also reduce contrast, soften shadows, and lower the strobe's power, but they may lower the color temperature of the strobe by 300-500 Kelvin. Diffusers are often used to reduce backscatter or when the strobe feels too strong.

Types of Strobe Lighting

Strobe lighting can be directed from various angles to achieve different effects:

  1. Front Lighting: Light from the front minimizes shadows and highlights colors, but can flatten details. It's typically easy to expose and is used when you need even lighting. A ring flash or internal camera flash can produce this effect.
  2. Side Lighting: Light from the side enhances texture and depth by creating dramatic shadows and high contrast. It’s effective for bringing out details, especially in subjects with rich textures, like an octopus.
  3. Backlighting: Light from behind the subject creates a glowing effect, particularly useful for translucent objects. It highlights shape and form while reducing saturation. This lighting works best with subjects like jellyfish or some corals.
  4. Top Lighting: A combination of front and side lighting, often used for macro shots. It mimics natural sunlight, producing softer shadows and highlighting the subject’s interior details, like inside a tunicate.

Shooting with Multiple Strobes

Using multiple strobes allows for more flexibility and creativity. A common technique for macro photography is using two strobes with different power settings:

  • The primary strobe provides the main light.
  • The fill strobe provides softer, secondary lighting to reduce harsh shadows.

This setup can be achieved in several ways, such as:

  • Using different strobes with varying power.
  • Placing one strobe closer to the subject.
  • Applying a diffuser to one strobe only.

Preventing Backscatter

Backscatter is a common problem in underwater photography, caused by particles in the water reflecting light back into the lens. Techniques to reduce backscatter include:

  • Moving the strobes further from the camera.
  • Using diffusers or snoots.
  • Reducing the amount of light that hits the water between you and the subject.

Choosing the Best Lighting Setup

There’s no universal “best” lighting setup. Each subject will respond differently to lighting types. Here’s a quick breakdown:

  • Frontlighting works for most subjects to bring out their color.
  • Sidelighting is ideal for showing texture and shape.
  • Backlighting is good for see-through or dreamy subjects. Try it to see what works best.

Single vs. Dual Strobes

While two strobes offer more flexibility and help reduce backscatter, a single strobe can still produce great results, especially in macro photography. The choice of one or two strobes ultimately depends on your preferences and the type of photos you want to achieve.

White Balance When Using Strobes

For accurate color, set your camera’s white balance to auto or adjust it to match the color temperature of your strobes. Most strobes emit light around 5500K, but diffusers can slightly reduce this, affecting the overall look of your photos. In wide-angle shots, the background's color will reflect the strobe's temperature, which might not give you the desired background color. To compensate, some advanced photographers add color correction filters to their strobes to adjust the color temperature.

Advanced Lighting Techniques

  1. Using a Snoot: A snoot is a tool that narrows the light beam, allowing you to focus light on a specific area, such as a small subject or particular detail.
  2. Kelvin Filters: Color correction filters can change the color temperature of your strobes to adjust the warmth or coolness of the light. For example, using 4600K filter can warm up the light, creating richer, warmer tones in tropical waters.
  3. Ring Flashes: These flashes offer shadow-free, even light for macro photography. They work similarly to front lighting, where light is cast directly onto the subject, but may not be TTL-compatible.

Underwater Strobes: Features, Comparisons, and Recommendations

Underwater strobes are crucial for quality underwater photography, reducing backscatter and providing better lighting for various shots. They are typically purchased as the second essential piece of equipment after the camera housing. Popular brands include INON, Ikelite, AOI, Backscatter and Sea & Sea. Here's a breakdown of the essential features and factors to consider when choosing the best strobe for your camera setup:

Key Strobe Features

  1. Strobe Power (Guide Number): Higher guide numbers indicate stronger strobes. This number is a product of the distance and aperture (f-stop) that can be properly illuminated at full power. Formula: Guide Number = Distance * f-stop.
  2. Recycle Rate: Faster recycle times (1-3 seconds) allow you to shoot more quickly without waiting for the strobe to recharge after each shot.
  3. Shots Per Full Battery Charge: Quality strobes typically offer 100-300 shots per full charge, depending on the battery and power settings used.
  4. Size and Weight: Smaller and lighter strobes are easier to handle but may offer less power. Larger strobes, such as those from Ikelite, often provide better performance at the cost of weight.
  5. Focus Light (Aiming Light): Helps with auto-focus in low-light conditions.
  6. TTL or RC Compatibility: TTL or RC (Through-the-Lens) systems allow automatic exposure control, simplifying the lighting setup.
  7. Color Temperature: Most strobes have a color temperature between 4700K and 5600K.
  8. Bulb Size: Larger or curved bulbs can provide more even light, though this difference is subtle.

Recommended Underwater Strobes

1. DSLR and Mirrorless Users:

  • Backscatter HF-1, (Backscatter MF-2 macro only)
  • Ikelite DS-230, DS-232, DS160
  • INON Z-XXX (announced 2025)
  • AOI UIS-P1 Ultra InTeLi Strobe
  • Sea&Sea YS-D3

2. Compact Camera Users:

  • Popular models include AOI Q1 or Q1RC, Sea & Sea YS-01 Solis, YS-03 Solis, INON S-220, and Ikelite DS-51 II. For more powerful all-in-one wide-angle shots and, the Backscatter HF-1 can be a very good upgrade.

Popular Strobe Models by Brand

AOI:

  • AOI UIS-P1 Ultra InTeLi Strobe: Powerful underwater strobe designed for precise lighting control, featuring a high guide number and fast recycle time, ideal for both macro and wide-angle photography.
  • AOI Q1: Compact strobe, manual flash only. Top choice for compact camera users and macro shooters.
  • AOI Q1RC: Compact strobe with manual control and support for the RC flash protocol, perfect for Sony and OM system users, as well as macro photographers.

Sea & Sea:

  • YS-D3: Offers powerful performance with fast recycle times, making it ideal for both compact and mirrorless camera users.
  • YS-01 Solis: Compact, affordable underwater strobe that offers reliable performance, ease of use, and compatibility with fiber optic cables, making it ideal for compact camera users and macro photography.
  • YS-03 Solis: Is a compact underwater strobe that offers TTL flash control but lacks manual flash settings, making it ideal for beginners seeking easy automatic exposure.

Ikelite:

  • DS-230, DS-232: For their powerful performance, fast recycle times, and long battery life, making them ideal for sync-only setups in underwater photography. DS160
  • DS-51 II: Ideal for compact cameras or DSLR/Mirrorless macro setups.

INON:

  • S-220: For its compact size, affordability, and suitability for beginner compact camera users.
  • Z-XXX: A newer model with more power for higher-end users.

TTL and RC Systems:

  • Sea & Sea and INON use TTL for their strobes, which mimics the camera's preflash via a fiber-optic cable, allowing for automatic exposure control without needing a TTL converter.
  • AOI and Backscatter use RC. The RC protocol, used by Sony and OM Systems, offers more accurate TTL flash control compared to standard TTL by improving communication between the camera and strobe.

Saving Money on Underwater Strobes: Used & Budget-Friendly Options

Underwater strobes can be a significant investment, but there are plenty of options available for those on a budget. We offer a selection of high-quality used underwater strobes, providing budget-friendly options without compromising performance. Whether you're a beginner or an experienced diver, our used strobes deliver reliable lighting solutions at a fraction of the cost of new models.

Conclusion

When selecting an underwater strobe, consider the power, recycle time, size, and compatibility with your camera system. AOI, Backscatter, Sea & Sea, Ikelite, and INON are reliable brands offering various options tailored to different budgets and camera setups. For DSLR and mirrorless users, consider more powerful strobes like the Backscatter HF-1, Ikelite DS232, AOI UIS-P1 Ultra InTeLi Strobe, or Sea&Sea YS-D3, while compact camera users can start with models like the Q1(RC), YS-01, or S-220.