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 Single Lens Reflex (SLR) Cameras are a common style of camera.  SLR’s allow the user to look into the viewfinder and see through the lens, sort of a “what you see is what you get” approach.  The main advantage of this type of camera is a versatility that allows the user to change lenses. A camera and interchangeable lenses create a “camera system”.  An underwater housing can be an excellent addition to the system.

Ikelite housings are available for Canon, Minolta, Nikon, and Pentax camera systems. Some other styles of camera can be housed “custom”, but this is slightly more expensive.

Some comments on cameras:

The best systems to put into housings are autofocus cameras.  These modern cameras automatically focus, adjust the light with TTL matrix metering, advance the film...

TTL exposure means “through the lens”. Inside the camera are some sensors very near to where the film is and they determine when the exposure is correct. Matrix metering means that it can compare the available light and the strobe light to determine when the exposure is correct. Many modern autofocus and TTL cameras have matrix metering but the Nikonos V does not.

Some cameras do not have autofocus but will adjust the light automatically. These will also link with the strobe in a TTL circuit.

Some SLR’s are manual cameras. This means that they can be used in the housing but they will need the most number of control linkages. The more control linkages, the more opportunities for difficulties. The best manual cameras to house must have some form of internal light meter. Without this feature, it’s a pretty useless exercise to house a camera.

Lenses

Lenses must be matched to the port used. For example, wide angle lenses need a wide angle port.

There are two neat things that a wide angle port will do:

By setting the focus of the lens on the camera at 12”, the optics of the dome port affects the focus and the color saturation. Practically everything in front of the camera housing will be in focus and the color will be intensified.

Close Up Photography

With a flat port, macro lenses can focus underwater from just a few inches in front of the camera to infinity. The length of the port is dictated by the maximum length of the lens.  Most macro lenses are between 50mm - 100mm; the greater number associated with the lens, the more telephoto the lens will be. For example, a 50 mm lens will focus on a small object at a distance of 9 inches away; a 100 mm lens will give the same size image of the small fish from a distance of 18 inches away. This is valuable because it is less frightening to the small fish and the photographer is more likely to get the shot.

Zoom

Autofocus zoom lenses have wonderful applications underwater.  A typical autofocus zoom lens is a 28 - 80 mm zoom. This means that in the 28 mm mode, it is a mild wide angle. In the 50 mm mode, it is a standard lens. In the 80 mm mode, it is a mild telephoto lens. The standard and telephoto modes are ideal for fish portraits. Many zoom lenses also have a macro mode which would make it ideal for close-up photography as well. This means that someone with a zoom lens can take wide angle, fish portraits, and macro all on the same dive. A +4 close up lens (available at camera stores) must be attached to the zoom lens and a special extended dome port must be used to take advantage of all aspects of the lens.

Strobes

At any depth below 10’, it is in the underwater photographer’s best interest to use a strobe. There is enough light to take photos, just that the color will not be as rich as we expect it to be. As with the ports, strobes must be matched to the needs of the lens.

Close Up Photography

Any of the Ikelite strobes can be used here, but the most common is the MV. All strobes will require a mounting bracket and a connecting cable. The cable must be co-ordinated with the type of camera being used. That means to say, is the camera operating under TTL exposure or manual exposure. TTL exposure requires extra wires in the cable and the cables are not interchangeable. Also, the cable is the weakest part of the entire system. An extra cable is a good insurance policy.

The AiN is an excellent strobe for close up, portrait, and mild wide angle photography (i.e., zoom lenses). As an additional feature, the AiN has a spotting light that helps in the autofocus process.

The Substrobe 150 or 300 are excellent strobes for wide angle photography. Each of these strobes covers a huge area with even lighting and offers multiple output settings.

While larger strobes can be used for the tasks of the smaller strobes, that is not always the case with smaller strobes. For example, the extreme wide angle coverage of a Substrobe 150 could be used for close up photography, however using a Substrobe MV for wide angle could result in an unevenly illuminated image (hot spot).