Lenses & Filters

Frequently asked questions

What is a wet lens and how is it different from a standard camera lens?

A wet lens (also called an add-on or snap-on lens) attaches to the outside of a camera housing or directly to the front of a dedicated underwater camera using a bayonet mount. Unlike the fixed lens inside the camera, a wet lens can be added or removed between dives without surfacing — simply snap it on at the beginning of the dive, remove it and clip it to a BCD D-ring if you want to switch shooting styles, and snap it back on at any point. This makes wet lenses extremely practical compared to changing the actual camera lens or entering a housing underwater. Sealife produces wide-angle, macro, and red filter wet lenses specifically for their Micro camera series and SportDiver housing.

Do I need a wide-angle lens or a macro lens for underwater photography?

Wide-angle lenses are the most broadly useful first addition — they allow you to get closer to subjects while capturing more of the scene, which reduces the water column between camera and subject and produces cleaner, more colourful images. They suit reef scenes, large fish, marine mammals, divers in the frame, and most general underwater shooting. Macro lenses are for extreme close-up work — tiny subjects like nudibranchs, blennies in holes, shrimp on coral, and abstract reef textures that the standard lens cannot resolve at the short focus distances needed. .

What does a red filter do for underwater photography?

A red filter compensates for the blue-green colour cast that occurs when shooting in natural light at depth. Water absorbs red wavelengths progressively — at 5 metres most red is gone and below 10 metres orange and yellow begin disappearing too, leaving images with that characteristic blue-green underwater tint. A red filter over the lens adds back red transmission, partially compensating for this absorption and restoring more natural colour balance to images shot in ambient light. Red filters are most effective in the 3 to 15 metre depth range where there is enough natural light to work with and enough red absorption to compensate. Below 20 metres, natural light is so reduced that an artificial light source becomes necessary — at those depths a red filter alone is not sufficient and a video light or strobe is the better solution for colour restoration.