Technique for small animals on a dark bottom

Snoot lighting

A snoot is a tube or a set of optics that narrows a strobe’s output to a small circle, so that the subject is lit and nothing else is. On black sand this does most of the work of a picture: the sand around a 3 cm shrimp is the same brightness as the shrimp until you stop lighting it, and a snoot is the difference between an animal on a beach and an animal on a stage.

Two kinds are in general use. A simple tube is cheap, forgiving of a knock and loses a lot of light. An optical snoot puts a lens in the path, holds a much harder edge and gives back two or three stops, at the price of needing to be aimed precisely. Either way the difficulty is aiming: the light circle is a few centimetres across at working distance and you cannot see where it falls until the strobe fires. An aiming light that is coaxial with the flash tube — not beside it — is what makes the thing usable, and it should be dim enough not to move the animal.

Work at one strobe first. A second snooted strobe from behind separates the subject from the background further, but two invisible circles are more than twice as hard to place as one. Set the aperture for the depth of field you need, then move the strobe closer or further to control exposure rather than changing the aperture.

Super macro

A true macro lens reproduces a subject at life size on the sensor. Below about 2 cm that is not enough magnification, and the choice is between a wet dioptre in front of the port, a teleconverter behind the lens, or an extension tube. A wet dioptre can be taken off in the water, which matters when the guide finds a frogfish two minutes after the pygmy seahorse; a teleconverter cannot, and commits the whole dive.

Everything gets harder at once. Depth of field at 2:1 is a millimetre or two even at f/22, working distance drops to a few centimetres, and the viewfinder darkens. The practical consequences: focus by moving the camera rather than by turning the ring, shoot at the moment the animal is still rather than continuously, and accept that the eye is what has to be sharp. Diffraction softens the whole frame past roughly f/16 on a cropped sensor and f/22 on full frame, so stopping down further buys depth of field at a cost that shows.

Black backgrounds

A black background is an exposure, not an edit. Set the shutter and aperture so that the ambient light records as nothing — in daylight on a shallow site that usually means the fastest shutter speed that syncs, and f/16 or smaller — then light the subject with the strobe alone. Anything the strobe does not reach stays black.

That works when there is water behind the animal. When the subject is sitting on sand with nothing behind it, the sand lights up and the result is grey, and the answer is a snoot or a change of angle: get low, shoot slightly upward, and put open water behind the head. Shooting down at a critter on the bottom is the single commonest reason a black background fails.

A black background is not always the right answer. It removes the habitat, and for a species whose interest is where it lives — a shrimp on a fire urchin, a crab in a tube anemone — the habitat is half the photograph.

Buoyancy over silt

Everything on a muck site is downstream of one skill. Silt lifted by a fin stays in the water for the rest of the dive, it ruins the pictures of everybody behind you, and on a good site it is the reason a guide will stop showing you things.

The habits that matter: be weighted correctly rather than heavily, and check it at the end of a dive with an empty cylinder, not the start. Fin from the knee with a frog kick or a modified flutter, never a full-leg flutter close to the bottom. Approach a subject horizontally and hover, rather than kneeling. If you must have a contact point, one finger on a bare patch of dead rubble or a single pointer stick is stable and does no damage; a hand planted in the sand does. Look behind you before backing off a subject, because the cloud you left is where you are about to reverse into.

Blackwater

A blackwater dive is made at night in open water over deep bottom, on a downline hung with lights, photographing the animals that rise from depth after dark — larval fish, cephalopods, pelagic molluscs, siphonophores and the juvenile stages of animals whose adults live on the reef. It is the same lens and often the same strobes as muck macro, used in a very different way.

The subjects are transparent, small, and moving in three dimensions, and autofocus struggles on all three counts. Manual focus set to a fixed distance and moved bodily is more reliable than hunting. A focus light that is strong and tightly focused earns its place here more than anywhere else. The dive itself is a matter of discipline rather than skill: stay on the line, keep a light on yourself, know your depth without having to think about it, and agree the recall signal before entry.

Gear notes

Nothing on this site is a review and nothing here is a recommendation to buy. What is worth stating is the order in which equipment stops being the limiting factor, because it is not the order most people buy in.

Lighting comes first: a snoot or a second strobe changes more pictures than a new body does. Focus light second — most missed macro shots are missed focus, not missed exposure. Optics third: a wet dioptre opens up a class of subject that no amount of sensor buys. The camera itself is last, and a five-year-old body with good glass and controlled light will outshoot a new one without either.

Equipment named anywhere on this site was bought and paid for by the person writing about it. See about & editorial policy.

Cameras and lenses used