SEA&SEA YS-D3 DUO High-Output Underwater Strobe | DS-TTL II, OM SYSTEM RC & GN33

Built for Serious Underwater Photography

Wide-angle underwater photography requires more than raw output. A strobe must spread light evenly across a broad foreground, recycle predictably, remain easy to control with gloves, and integrate correctly with the camera’s flash system.

The YS-D3 DUO combines a high guide number of 33 with SEA&SEA’s proprietary light-distribution optics. Its dual discharge tubes and aspherical toroidal lens are engineered to produce broad, even illumination with reduced edge falloff, making the strobe particularly effective with fisheye and wide-angle lenses.

Three Shooting Modes for Different Camera Systems

The YS-D3 DUO uses a color-coded mode switch to separate its automatic and manual exposure systems. This makes the selected operating mode easier to confirm during daylight, low-visibility dives, and night photography.

Highly Refined DS-TTL II Performance

The YS-D3 DUO uses a redesigned light-receiving sensor to improve DS-TTL II exposure accuracy. This optical TTL system responds to the camera’s flash sequence and adjusts strobe output automatically, making it useful when subject distance changes quickly.

In DS-TTL II mode, exposure compensation can be adjusted directly from the strobe through a range of +2.0 to -2.0. This allows the photographer to retain automatic exposure while intentionally brightening or reducing the strobe contribution.

Dedicated RC Mode for OM SYSTEM and Olympus Cameras

The YS-D3 DUO was developed with input from OM Digital Solutions to support the RC flash system used by compatible OM SYSTEM and Olympus cameras. In RC mode, the camera measures exposure through the lens and controls strobe output as part of the camera’s flash system.

Exposure compensation can be adjusted from the strobe or, with compatible cameras, through the camera controls. RC operation can also reduce the amount of light required from the camera’s internal flash, which may help conserve camera battery power.

Eleven-Step Manual Power Control

Manual operation provides 11 clearly marked guide-number settings: 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, and 33. This broad adjustment range supports low-output macro lighting as well as full-power wide-angle photography.

Separate manual modes are provided for cameras with and without pre-flash. This helps the strobe synchronize correctly with different camera flash sequences.

High-Output Dual-Tube Flash System

Two discharge tubes allow the YS-D3 DUO to reach a maximum guide number of 33. This high output is especially valuable when the strobe is positioned farther from the subject, when smaller apertures are used, or when lighting large foregrounds with wide-angle and fisheye lenses.

High output also provides more flexibility for dual-strobe systems because each strobe can be positioned farther outside the lens axis while still delivering sufficient light to the subject.

Uniform Light Distribution

SEA&SEA’s aspherical toroidal lens is positioned in front of the flash tubes to distribute light smoothly across the beam. The design helps reduce pronounced center hot spots and uneven illumination near the edges.

More uniform coverage is particularly important in wide-angle photography, where an uneven strobe beam can create bright central areas and underexposed corners across the foreground.

Adjustable Beam Coverage

The included diffuser broadens and softens the strobe output for general wide-angle use. The optional dome diffuser creates exceptionally broad coverage for fisheye photography and soft-light applications.

Designed for Underwater Operation

The YS-D3 DUO places particular emphasis on underwater usability. Its mode and power controls use large, non-slip dials with different heights, helping divers identify and turn them while wearing thick gloves.

The controls use stepped click positions to reduce accidental changes. A backlit panel changes color according to the selected operating mode, making the current configuration easier to identify on night dives or inside dark wrecks and caverns.

Near-Neutral Underwater Balance

With a ball mount and clamp installed, the YS-D3 DUO is designed to approach neutral buoyancy. This reduces the effort needed to reposition the strobe and helps prevent a heavy lighting system from pulling the housing to one side.

Balanced strobes are easier to adjust smoothly and can improve the overall handling of a larger mirrorless or DSLR underwater system.

Dual-Level LED Target Light

The integrated target light offers two output levels: 300 lumens and 150 lumens. The higher setting makes the beam direction easier to see, while the lower setting provides a less intense aiming light for night dives, shy subjects, and close-range macro work.

• Helps confirm the direction of the strobe beam
• Can assist autofocus in dark water
• Useful when positioning dual strobes
• Two brightness levels suit different subjects and dive conditions

Fast Bayonet Battery Access

The YS-D3 DUO uses four matching AA batteries. The battery compartment opens with a bayonet-style mechanism rather than a long screw thread, reducing the amount of rotation and force required during battery changes.

This design also minimizes twisting stress on the battery-cap O-ring during normal opening and closing.

Flexible Triggering and Mounting Options

The strobe body includes a guide hook for cleaner fiber-optic cable routing. Manual and supported automatic shooting can be configured through compatible optical triggering systems, while selected housings and converters may also support a sync-cord connection.

A straight ball base is included. Depending on the arm system and desired positioning, the strobe can also be configured with an optional YS Mount Strobe Adaptor or Strobe Ball Base 35.

Best Uses Underwater

Compatibility and Custom Configuration

• Use DS-TTL II for compatible TTL operation with most non-OM SYSTEM cameras
• Use RC mode with compatible OM SYSTEM or Olympus cameras configured for RC flash
• Use Manual 1 for compatible cameras with pre-flash
• Use Manual 2 for compatible cameras without pre-flash
• Compatible housings with the appropriate connector or converter may support sync-cord operation

Model and Color Availability

Technical Specifications

What’s in the Box

• SEA&SEA YS-D3 DUO underwater strobe
• Straight ball base
• Standard diffuser