- An aperture of the lens – adjustment of the iris, measured as an f-number, which controls the amount of light entering the lens. Aperture also has an effect on focus and depth of field, namely, the smaller the opening aperture), the less light but the greater the depth of field–that is, the greater the range within which objects appear to be sharply focused.
- Shutter speed – adjustment of the speed often expressed either as fractions of seconds or as an angle, with mechanical shutters of the shutter to control the amount of time during which the imaging medium is exposed to light for each exposure. Shutter speed may be used to control the amount of light striking the image plane; ‘faster shutter speeds that are, those of shorter duration decrease both the amount of light and the amount of image blurring from subject motion or camera motion.
- White balance – on digital cameras, electronic compensation for the colour temperature associated with a given set of lighting conditions, ensuring that white light is registered as such on the imaging chip and therefore that the colours in the frame will appear natural. On mechanical, film-based cameras, this function is served by the operator’s choice of film stock. In addition to using white balance to register the natural colouration of the image, photographers may employ white balance to aesthetic end, for example, white balancing to a blue object in order to obtain a warm colour temperature.
- Metering – measurement of exposure at a mid-tone so that highlights and shadows are exposed according to the photographer’s wishes. Many modern cameras feature this ability, though it is traditionally accomplished with the use of a separate light metering device.
- ISO speed – traditionally used to set the film speed of the selected film on film cameras, ISO speeds are employed on modern digital cameras as an indication of the system’s gain from light to numerical output and to control the automatic exposure system. A correct combination of ISO speed, aperture, and shutter speed leads to an image that is neither too dark nor too light.
- Auto-focus point – on some cameras, the selection of a point in the imaging frame upon which the auto-focus system will attempt to focus. Many SLR single Lens Reflex cameras feature multiple auto-focus points in the viewfinder.
- The body –The body is the box, to which everything else is attached. Can be made from metal, plastic, space-age composite, wood, cardboard, or just about anything opaque. As well as the attaching point, the body holds the film. In the case of a view camera, the body is simply a frame that holds a film holder on one side and a bellows, or extendable tube on the other, which is attached to a separate lens-holding frame.
- Viewfinder — The viewfinder is what you look through to compose the picture. Most often integral to the body, pro cameras have viewfinders that can be switched. The viewfinder contains a lens, through which you look, a mirror, and a ground glass view screen, which again, in pro cameras, can be replaced or swapped for different types. Most viewfinders only show some 85-90% of the scene, so watch your edges, and get closer.
- Shutter release — Usually located on the right front as you hold the camera), the shutter release is the button you push to, hey, release the shutter. The button may be threaded to accept a cable release, which you attach as an extension, and use when you want to eliminate vibration. Mounted with the shutter release, at least on those old-timey cameras, is the film advance lever. Many newer cameras with auto winders built-in don’t have a film advance lever.
- Shutter speed dial — Usually located on the right front as you hold the camera), closer to the viewfinder. Many newer, electronic cameras don’t have this dial, and you set the shutter speed using buttons or different dial, usually located near the release on the body. The shutter speed dial will have a series of numbers, usually from 8 or 4 to 1000 or 2000. These are shutter speeds and are parts of a second. Also, you may see A or P for automatic or program, T for time, which opens the shutter when you press the release and leaves it open until you press it again. B is the bulb setting, which keeps the shutter open for as long as you keep the release held down. There will also be a flash-sync speed, which is the speed setting for your camera when using a strobe.
- Rewind/ASA dial — This, at least on cameras without a built-in winder, is a kind of multi-function knob. The upper part has a small flip-out crank, which is used in conjunction with a release button on the bottom of the body to rewind the film back into the canister. Pull the crank up, and it releases the camera back, to load and unload film. The bottom part is the ASA, or film speed, setting. Pulling up on the outer ring allows you to rotate a dial to change the ASA setting. Cameras that do not have either of these will have a rewind switch or rewind the film automatically when you reach the end of a roll. There will be a lever or release for the back, usually on the side of the body. The ASA may be set automatically reading the DX code from the film canister, with an override available through the onboard computer.
- Lens release — A button or lever which unlocks the lens for removal, the lens release is one of the few controls on the front of the camera which hasn’t been replaced by a selection in an LED menu. Work the release and twist the lens to remove, with bayonet-mount lenses. To replace the lens, line up the slots, or two dots one on the lens and one on the body and twist until the lens clicks into place. Do not force the lens! If it is lined up properly, it should go right on.
- Casing and Viewfinder — The camera casing is the solid outer shell that provides protection for the inner parts. The casing also helps keep light out of the camera, preventing light from exposing the film. The viewfinder is used by the camera operator to aim and focus the image and adjust the settings.
- Lens and Mirror –The lens allows light to enter the camera and focuses the light on the film. It also allows light to reflect off the mirror, allowing the operator to see the image to be photographed in the viewfinder. An image that is not focused on the viewfinder will appear blurry when printed. The mirror is only in use when the shutter is closed. It allows the operator to see the image in the viewfinder to prepare the image to be photographed. When the shutter is opened, the mirror moves up allowing light to enter the camera and exposing the film to the lighted image.
- Prism — The prism refracts light, allowing the operator to see the image in the viewfinder when the shutter is closed.
- Aperture and Shutter Speed Dial — The opening in the lens that controls the amount of light allowed into the camera and the length of time the film is exposed to light is called the aperture. The shutter speed dial is set by the camera operator and regulates how long the aperture stays open. The slower the shutter speed, the lighter the aperture allows into the camera; a slow shutter speed would be set around 60.
- F-Stop Ring and ASA Dial — The F-Stop ring has settings from 2 to 22, with 2 being the largest and 22 the smallest. These settings are for the size of the aperture opening when the picture is taken; the smaller the setting, the less light is allowed into the camera to expose the film. The ASA dial is set according to the speed of the film used in the camera. The faster film is used for fast-moving action and low light levels; a film with a setting of 200 or above is classified as fast.
- Film Advance Lever, Rewind Crank and Frame Advance Box: The film advance lever is used to advance the film through the camera. The frame advance box displays the number of pictures taken and helps the operator judge how many pictures are left on a roll of film. The rewind crank is used when a roll of film is finished and is used to rewind the exposed film back into the canister.
While the above controls/parts are pretty much standard, there are more that are less so. The first is a depth of field preview. This is a button or lever, which when manipulated, will stop down the lens to the aperture setting selected, allowing you to look through the viewfinder and actually see the depth of field. An excellent thing, with one problem: many 35mm SLRs have viewfinders that are too small and dim to see anything once you’ve stopped down past about ƒ/8.
Another control is a self-timer, a button or switch which will release the shutter after a given interval so that you can be in those wonderful group pix with everyone else. Usually, there is a socket for a sync cord a small double -circle), which is used to attach the camera to a strobe unit. There may be a manual shutter release, for use when batteries are well and truly gone.
Cameras that do not have auto-advance and rewind usually have a small button on the bottom of the body which must be depressed when rewinding the film. This button disengages the film advance drive mechanism. If you don’t hold this down and insist on rewinding the film, you will do one of several bad things: break the rewind lever/handle, rip the film, and/or strip the gearing The basic idea behind the photographic camera has not changed much since its invention, although new advancements such as digital technology have changed the art form. Knowing the mechanism behind a camera gives the photographer a better understanding of the craft of photography.