Underwater housings for SLR cameras

by Brian Pitkin

Choosing a housing

Your choice of SLR housing may depend on whether or not you already have a camera that you want to house.

Underwater SLR camera housings are only available off-the-shelf for a relatively small number of the makes and models of SLR land cameras, so there may not be a suitable housing off-the-shelf for your existing camera. You may therefore need to consider which camera / housing combination you need. Although some manufacturers will make a custom housing for you, this is likely to cost more. Or you could consider making your own, as several BSoUP members have done.

Fortunately for underwater photographers, housings are available off-the-shelf for many of the Nikon and Canon models and for some of the Mamiya, Minolta, Olympus, Pentax, Vivitar and Yashica models of SLR cameras.

If you already own an SLR camera from one of the manufacturers listed above, you can use the table below to check if there is a housing available off-the-shelf for your make of camera. If your camera is not listed, then you should consider building or having built a custom housing or purchasing a new or second-hand camera and an appropriate housing. With the increasing emphasis on digital cameras for the land photographer there is quite a competitive market for second-hand SLR cameras. All of the housing manufacturers listed below make housings for one or more Nikon SLR cameras, which are probably the most widely used by underwater photographers.

Currently, the most popular choice amongst BSoUP members is a Subal housing for a Nikon F801 or F90, although some members use others, including Aquatica. Although with the availability of the new Nikon F100 and suitable housings this will almost certainly change in the future. Their choice, however, may be dictated by availability and proximity to a retailer within the UK. My wife, in contrast, uses a Hugyphot housing for a Pentax LX purchased at a time when Hugyphot were available in the UK . A number of other successful photographers use a housing from other manufacturers or a housing that they have built themselves.

Polycarbonate, aluminium or alloy

Housings are usually made from injection moulded polycarbonate, aluminium or alloy. Polycarbonate housings tend to be cheaper than their aluminium or alloy equivalents, which can be more expensive than the camera they are designed to house.

Ikelite and Nimar each make two different sized housings (Nimar 2 and 3 and Ikelite TTL SLR-AF and MD-size respectively) from polycarbonate for a range of different makes and models of SLR camera, although the choice of controls available for Ikelite housings varies considerably, dependent on the camera housed .

These 'one size - fits all', polycarbonate housings tend to be bulkier and more buoyant than aluminium housings designed for a specific camera. Their one major advantage is that you can see when they leak, if you have failed to maintain the all-important o-ring seals. They will also accommodate more water before the camera gets wet. Although tough, polycarbonate housings can easily be scratched and cracked if abused, but they will not corrode.

If you want to house a Minolta, Olympus or Yashica SLR camera, you currently have no option but to choose a polycarbonate housing.

Other manufacturers housings, made from aluminium or alloy, tend to be smaller and less buoyant than their polycarbonate equivalents. Aluminium and alloy housings, usually designed for a specific make and model of camera, will fit so snugly that there is little space between camera and housing. In the event of a leak the camera will almost certainly be ruined. Aluminium and alloy housings are more robust than polycarbonate housings and can take a fair bit of abuse without coming to much harm, although they can corrode, particularly around stainless steel fittings (where present), if not thoroughly soaked in freshwater after immersion in sea water. Some housings come complete with a leak detector and for those that don't, you should purchase one from an independent supplier.

Catches

The front and back part of a housing may be secured either by catches or screws. It is possible to under or over tighten screws, either of which can lead to a leak.

Ergonomics

The design of the housing should be such that the primary controls are readily to hand. At the very least you should be able to hold the housing comfortably whilst still being able to press the shutter release and focus in a controlled manner. As a test, hold the housing by its handles or grips at eye-level and try half depressing the shutter release, with your fore-finger, to activate the camera's LED display without taking a picture, and focus on something using the thumb and fore-fingers of the other hand. If it doesn't feel comfortable and natural check to see if the handles can be adjusted or replaced with more suitable ones for your particular hand size or, if not, try a different make of housing.

External controls

All housings include external controls for the shutter release, focus and aperture. Most housings also include other external controls e.g. on/off, shutter speed , Film speed, exposure compensation, manual, single or continuous exposure and spot, centre-weighted or matrix metering etc.

There will also be one or more bulkhead connectors to which your flash or flashes connect externally. Although you might be tempted, if money is no object, to buy the housing with the greatest number of controls for your chosen camera, you should think carefully about which you actually need to use underwater. The simpler you make it the less chance of error!

You will need to consider the ease with which you can compose and focus your camera once it is housed. Not all SLR cameras have built-in viewfinders which allow you to see 100% of the area which will be exposed to the film when you press the shutter. Cameras with Sports or Action finders give better coverage than others. Make the wrong choice of housing and its built-in viewfinder port may reduce this area further. As a general rule the closer you can get your eye to the housed camera's viewfinder whilst wearing a mask, the greater your chance of seeing the same area that is exposed to film.

The addition of a magnifying lens to the camera's or housing's viewfinder may enable you to see more of the subject area, but it will also make the subject look smaller and therefore make it more difficult to focus on and compose your subject. Of course, if you are using auto-focus then focusing should not be a problem.

Ports

You should think about the lens or lenses you want to use underwater. The prices quoted for most housings do not include lens ports.

Most BSoUP members use a 50 mm and/or 105 mm macro lens and a 20 mm wide-angle, and some find that a 16 mm fish-eye and a zoom lens can be quite useful underwater. You will need different ports to accommodate the length and angle of each different lens. If you are buying your first housing, then start with a macro lens and port and master this before investing in additional lenses and ports.

Ports generally use a bayonet type fitting, sealed by a serviceable o-ring, to the front part of the housing. Glass ports are usually better optically than perspex, and less easily scratched.

Macro lenses work perfectly well with a flat port, but wide-angle lenses need a dome port. The reasons for this are that a flat port reduces the angle of a wide-angle lens; causes colour distortion at the edges of the frame, causes geometric distortion and reduces the focusing range of the lens, which can only be corrected with a hemispherical dome port. Usually the more complete a hemisphere the better the optical quality, but larger domes can be almost as bulky as the housing and a greater risk of damage.

Dome ports introduce further problems, which require the addition of a positive lens or diopter to the primary wide-angle lens of the camera to compensate for the negative effects of the dome. The manufacturer or retailer should be able to advise you as to the strength of the required lens. Once you have the correct diopter for your lens/dome combination you should be ready embark on wide-angle photography.

Domes which are sold for more than one wide-angle lens are likely to give better results for one of the lenses than the others. Housed zoom lenses should be of the type in which the lens does not change length, focusing being achieved internally.

Flash attachments and connections

Your flash connects externally to a bulkhead connector on the housing. Most bulkhead connectors accept Nikonos type flash plugs. If you want to use multiple strobes, say a master to light the subject and bring back the colour and a slave to fill in some of the shadow, you should purchase a housing with two bulkhead connectors, although it is possible to purchase a splitter to connect two flash units to a single bulkhead connector. Connection between the bulkhead and the camera is via a cable either to the camera's hot shoe (TTL makes and models) or x-synch (manual makes and models e.g. Pentax LX).

The flash arm may be attached directly to the handles of the housing or to a tray secured to the base of the housing, dependent on make. Of course, if you are only using one of the currently available ring flash units for macro photography, then you will not need flash arms. These units fit onto the macro port, although they do produce a very flat image.

O-rings

Just like amphibious cameras, housings rely on o-rings to maintain their water-tight integrity. The number of o-rings will vary from one model to another and from one camera to another, dependant on which external controls are available. Generally, as in the Nikonos range of amphibious cameras, there are only two easily serviceable o-rings, one to seal the front to the back of the housing and the other to seal the lens port to the front of the housing. However, the o-rings sealing the control levers can certainly be serviced more readily than those of a Nikonos. The more external controls there are, the greater the potential risk of flooding, so you should have your housing regularly serviced if this is not your forte.

Accessories

There are a wealth of accessories available from the major housing manufacturers and others.

Handles or trays to attach flash arms, are a must. Wide-angle photography requires longer flash arms than macro photography, unless you are prepared to hand hold your flash unit. If you intend to hand-hold your flash unit when taking pictures, then you will need a flash arm that, although securely attached to the housing, can be easily be detached.

A leak-detector, if not supplied with the housing, is an essential item for any camera system. No matter how careful you are there will always be that one occasion when you haven't checked the o-rings thoroughly or secured the front and back parts of the housing or port before entering the water.

A lanyard is a must. Not only will it provide a means of allowing you to free your hands in the event of an emergency, it will provide a means of passing the camera safely in and out of the water.

A spotting torch ot laser pointer attached to your flash unit can help ensure that the flash is illuminating your chosen subject.

A light meter attached to the housing can also be very useful, even if your camera has a built in meter.

But remember, the simpler you make it, the more likely you are to take consistently good shots.

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