(Fig 4) A memorable photograph takes a command of the basics and pre-planning.

The basics of photography will be helpful in learning to control your camera, giving you the ability to produce the best final image. Modern digital cameras are remarkable tools that enable you to respond visually to the world around you. With your eyes you usually focus only passively, without emotion, intellectual thought or physical response. Taking a photograph, on the other hand, requires decisions about the images you want to make and how you want others to see them. The emotion of a photograph starts with seeing the photograph before it is taken. In the end, a really great and memorable photograph is more about the photographer and a little luck than the equipment you are using (Figure 4). Many times persistence can be as important as skill.

The Basic

Holding Your Camera
One of the most important parts of taking a photograph is controlling the motion of the camera. A steady camera will give the sharpest image. Whether left or right handed, you should hold the camera with your elbows close to your body as a brace. If possible use both hands, but when you are using one hand (as in some of the clinical shots when holding a mirror), hold firmly with the camera's built in grip or an added pistol grip. A tripod is imperative for longer exposures, but for our uses will not be necessary and in fact is a hindrance. As a rule of thumb however, the slowest shutter speed you can use to get the maximum sharpness while hand holding a camera is 1/the focal length of the lens with ambient light. You can typically go slightly outside this rule of thumb depending on how large the final image is going to be, the shutter speed and the sensitivity (ISO) of the sensor and by using a strobe. It is so important to use good bracing technique to hold the camera steady.

The Lens, Aperture and Focusing
The lens holds different types of glass that focus the light on the electronic sensor. The light passes through an adjustable diaphragm (aperture) that opens and closes to change the amount of light (f/stop) and is controlled either automatically or manually. On the barrel of the lens will often be an area with grooves and or ridges that provides a good grip for turning the lens barrel that focuses the lens or can be automatic.

Light passes through the lens and exposes a light sensitive sensor.
The type of lens affects the image. The cost of the lens typically reflects the quality of light that can pass through it. The price of the lens typically will increase as the fineness of the lens grinding process increases, the greater the magnification, the higher the light condensing properties and the more complex the mechanisms. A fast lens will have a larger aperture capability (lower f-stop) that allows for the collection of more light in a given time and will be considerably more expensive. For our purposes, a fixed focal length (typically around 100mm) lens will be desirable, especially for intra-oral macro photography but a higher quality telephoto lens can serve he purpose of several fixed focal length lenses for portrait shots. Digital cameras allow you to view the image at the exposure time and allow you to have a digital darkroom because of rapidly evolving technological changes in both hardware and software.

Exposure is determined by the amount of light and is controlled by time and aperture.
The image is recorded on the electronic sensor and is directly proportional to the amount of light that strikes the surface. The ISO (International Standards Organization) setting on a digital camera will affect the sensitivity to light (the higher the ISO, the more sensitivity). Bright light has more energy than dim light, and the amount of time the light strikes the film or sensor will vary inversely to the amount of light energy at a given exposure. We can control the exposure by controlling two factors; the amount of time the sensor is exposed to the light (shutter speed) and the size of the opening the light passes through (aperture). Think of the exposure as a bucket of water at a certain level. When filling the bucket with a fire hose (large aperture) less time will be needed than if filling the bucket with a straw (small aperture).

Dr Rhys Spoor DDS Aesthetic & Restorative Dentistry - Providing services in cosmetic and sleep dentistry to the area of Seattle, Washington.

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