Lights & Strobes

What to look for in an underwater video or photo light

Frequently asked questions

What is the difference between a video light and an underwater strobe for photography?

A video light (also called a continuous light) emits a constant beam that illuminates your subject for the full duration of your recording. It allows you to see exactly how the light is falling on the subject in real time and allows the camera's autofocus to work in low-light conditions. For video, continuous lighting is essential. For still photography, a dedicated underwater strobe (flash) fires a single, brief, extremely powerful burst of light at the moment of exposure — far brighter than any continuous light could maintain over time. The burst duration is short enough to freeze subject motion. Still photographers typically use strobes for the dramatic improvement in colour accuracy and subject sharpness they provide. Video shooters use continuous lights. Some divers who do both carry both types.

How wide a beam angle do I need for underwater video lighting?

For underwater video at typical shooting distances of 0.5 to 1.5 metres, a beam angle of at least 100 degrees provides even coverage without the distracting bright centre hotspot that narrower beams produce on video. Wide-angle video shooting with a dome port at closer distances may require 120 to 150-degree beam coverage for the entire frame to be illuminated evenly. For macro video shooting at very close distances (5 to 15cm), a narrower beam is acceptable because the subject area is small. Big Blue video lights in our range are available in wide-angle flood configurations specifically designed for even coverage in underwater video applications. Using a single video light positioned off-centre on a tray arm typically produces better results than a single centred light, which creates flat, shadow-free but dimensionless illumination.

What is a red focus light and why is it used for underwater photography?

A red focus light emits a continuous red beam used to assist camera autofocus in low-light conditions without activating the "flee response" in shy or sensitive marine life. Most fish and invertebrates cannot perceive red wavelengths well — what appears to us as a visible red beam is essentially invisible to most marine animals. A white continuous light of equivalent brightness would cause fish to dart away before the camera could focus and capture the shot. Red focus lights are particularly useful for macro photography of nudibranchs, shrimp, blennies, and other small, skittish subjects that are easily startled. Most Big Blue video lights and some standalone focus lights in our range include a red focus mode in addition to the primary white output.

Do I need a video light for shallow snorkeling photography?

In water shallower than about 3 metres with good sunlight overhead, natural light produces vivid, colourful images without supplemental lighting. As you descend beyond 5 metres, red and orange wavelengths begin disappearing and a video light becomes increasingly valuable for colour restoration. For snorkeling at the surface in tropical conditions, a video light is generally not needed. For any scuba photography deeper than 5 to 8 metres, even a modest video light of 1000 to 2000 lumens makes a visible difference in colour and image quality. For macro photography at any depth, a small video light or macro strobe dramatically improves both focus assistance and image quality regardless of depth.

What is backscatter and how do I prevent it in underwater photos?

Backscatter appears as white speckles or streaks across underwater images — caused by suspended particles (sand, plankton, marine snow) in the water column reflecting the camera's own light back into the lens. It is most severe when the light source is mounted directly in front of the camera lens, which maximises the return of reflected light. The primary prevention is to move the light source away from the lens on an arm — the farther the light is offset from the lens axis, the more the reflected light from particles travels away from the camera rather than back into it. Shooting with good buoyancy so you do not stir up sand is equally important. In water with very high particle content (common in Canadian lakes), even well-positioned lights cannot fully eliminate backscatter — shooting upward at subjects against the blue-lit water column minimises the particle volume between camera and subject.