Basic Photography Terms

In the previous blog posts we explored what photography is and also spoke about the history of photography. But in order to be able to speak about photography one should be familiar with basic photography terms. Below you will find an alphabetically sorted list of terms commonly used in photography:

The maximum angle a lens covers in the field. Measured in degrees, and qualified by terms such as wide-angle, normal, and telephoto. A wide angle lens has a wider angle of view than a telephoto lens. A 135mm lens on a 35mm SLR covers an 18-degree angle of view; a 28mm lens covers a 75-degree angle of view.

The opening of a lens, the size of which is controlled by a diaphragm. The term is commonly used to designate f-stops, such as f/4, f/5.6 etc., which are actually arrived at by dividing the focal length of the lens by the diameter of the aperture. Thus, f/11 on a 110mm focal length lens means the opening is 10mm. The wider the opening, the lower the f-number, the more light is let through the lens. Each step in aperture represents a halving or doubling of light. Thus, f/8 allows in half as much light as f/5.6, and twice as much light as f/11.

Long-lasting. In processing, those procedures that help insure stability of the image. Also, storage materials that will not damage photographic film and paper, or computer-produced prints.

Any light not directly produced by the sun. Can be tungsten, flash, household bulbs, sodium vapor street lamps, etc. In many cases, the color produced by artificial light is deficient in the blue end of the spectrum, thus daylight-balanced color films will record the light as being warm/red/amber. Tungsten-balanced slide films, or color-balancing filters over the lens will generally correct this problem. In some cases, color print film can be re-balanced when prints are made.

A method of exposure where aperture and shutter speed settings are first read, then set, by the camera’s exposure system. Various autoexposure modes allow for customization or biasing the readings.

A method of focusing where focusing distances are set automatically. In 35mm SLRs, a passive phase detection system that compares contrast and edge of subjects within the confines of the autofocus brackets in the viewfinder and automatically sets focusing distance on the lens. Autofocusing motors may be in the camera body or the lens itself. Active IR (infrared) autofocusing systems may also be in 35mm SLRs in the form of beams in dedicated autofocus flash units, or, in a few models, built into the camera itself. Commonly found in amateur lens/shutter cameras. These beams are emitted from the camera or flash, bounce off the subject, then return and set focusing range.

The light that’s normal in a scene, although the term is generally used when the light level is low. Available light shooting usually involves fast film, low shutter speeds and apertures, and/or the use of a tripod.

A shutter setting that indicates that the shutter will remain open for as long as the shutter release is pressed. The term originated with the rubber air shutter bulbs used to operate shutters in the old days. B settings are generally used in nighttime and time/motion study photography.

A photographic film or paper used to create monochrome images. Though we think of black and white mainly in terms of a gray scale, prints can have a wide variety of subtle tones, from blue- to brown-black. Though the overwhelming majority of photography today is shot and printed in color, black-and-white has attracted a fiercely loyal and dedicated group of photographers.

Unsharpness because of the movement of the camera or subject during exposure. Blur can be used for many creative effects. In computer imaging, the use of Blur controls to selectively soften parts of the image.

Making exposures above and below the “normal” exposure, or overriding the exposure suggested by the camera’s autoexposure system. Useful as a fail-safe method for getting “correct” exposure in difficult lighting conditions. Bracketing can also be used to make subtle changes in the nuance of tone and light in any scene. With slide film, bracketing will show an effect in 1/3 stop increments; with negative film a full stop of bracketing is advised.

The luminance of objects. The brightness of any area of the subject is dependent on how much light falls on it and how reflective it is. Brightness range is the relationship we perceive between the light and dark subjects in a scene. Brightness contrast is a judgment of the relative measure of that range, such as high, low, or normal. Brightness values are sometimes referred to as EV (exposure values), a combination of aperture and shutter speed. Brightness values in the scene are translated to tonal values on film.

A light-tight box containing light sensitive film or sensor that is used to make images. Today’s cameras incorporate microprocessors and sophisticated exposure systems; in a sense, the instrument itself mirrors the age, just as the pictures it makes reflect the world in which we live.

For charged couple device; the sensor used by most digital cameras, and in flatbed scanners.

The Kelvin scale, which is defined in degrees. It is used as a standard for balancing daylight films (approximately 5500 degrees K) and tungsten-balanced film (approximately 3200 degrees K.) Color conditions that vary from the standards will create a color cast in photographs made with these films, e.g., a daylight film used with artificial light will record with an amber cast; a tungsten film used outdoors will record with a blue cast.

The arrangement of subject matter, graphic elements, tones, and light in a scene. Can be harmonious or discordant, depending on the photographer, his or her mood, and the subject at hand. There are no set rules, just suggestions; successful compositions are ones that best express particular feelings about the subject or scene.

The relationship between the lightest and darkest areas in a scene and/or photograph. A small difference means low contrast; a great difference high contrast. High contrast scenes usually cause the most exposure problems; however, their difficulty can mean they hold the potential for more expression. Though contrast is often linked with scene brightness, there can be low contrast in a bright scene and high contrast in dim light. Contrast can also describe attributes of color, composition, and inherent qualities of film.

To select a portion of the full-frame image as the final picture. Cropping is done in the darkroom or computer environment by the photographer, or by an appointed surrogate in a commercial photo lab.

The work space for developing and printing photographic film and making prints.

The zone, or range of distances within a scene that will record on film as sharp. Depth of field is influenced by the focal length of the lens in use, the f-number setting on the lens, and the distance from the camera to the subject. It can be shallow or deep, and can be totally controlled by the photographer. It is one of the most creative and profound effects available to photographers.

A series of chemical and physical actions done in a commercial lab or the home darkroom that converts light-struck film to an image that can be viewed directly or printed; making prints from negatives.

The computer and image editing and manipulation programs.

The conversion of analog (film, print) information to digital form by use of a scanner, digital sensor or camera.

Known as a flash gun, strobe, or speedlight, it consists of a gas-filled tube that is fired by an electrical charge. It can be mounted directly on the camera hot shoe (which links the shutter firing to the flash firing), or on a bracket or stand and be connected to the camera via a sync cord.

The amount of light that enters the lens and strikes the film or sensor. Exposures are broken down into aperture, which is the diameter of the opening of the lens, and shutter speed, which is the amount of time the light strikes the film. Thus, exposure is a combination of the intensity and duration of light.

Light reading instruments that yield signals that are translated to f-stops and shutter speeds. Reflected-light meters read light reflected off the subject; incident meters reads light falling upon the subject. All in-camera meters are of the reflected-light type.

A series of numbers designating the apertures, or openings at which a lens is set. The higher the number, the narrower the aperture. For example, f/16 is narrower (by one stop) than f/11–it lets in half as much light. An f-number range might be f/2.8, f/4, f/5.6, f/8, f/11…To find the next aperture in a narrowing series, multiply by 1.4. F-numbers are arrived at by dividing the diameter of the opening into the focal length of the lens, thus a 10mm diameter opening on a 110mm lens is f/11. Alternately used with f-stops.

Flash used outdoors, generally to balance a subject that is backlit. Can also be used to control excessive contrast, add light to shadows, or brighten colors on an overcast day.

Any transparent accessory added to the light path that alters the character of the passing light. With film, filters can alter contrast, color rendition, or the character of the light itself (diffusion, diffraction, etc.) In printing, variable contrast filters are used to evoke different contrast grades from variable contrast black and white paper. In computer imaging software, a set of instructions that shape or alter the image information.

A compilation of light sensitive silver salts, color couplers (in color film), and other materials suspended in an emulsion and coated on an acetate base. The storehouse of our visions, nightmares, and dreams.

The distance from the lens to the film plane or sensor that focuses light at infinity. The length, expressed in millimeters, is more useful as an indication of the angle of view of a particular lens. A shorter focal length lens, such as a 28mm, offers a wider angle of view than a longer one, such as 100mm.

Causing light to form a point, or sharp image on the image sensor or film.

The size of the film, thus the camera that uses such film. Large format refers to 4×5 inches and larger; medium format uses 120 or 220 (6cm wide) film. Smaller formats include 35mm and 24mm. In computer imaging, the file structure, or “language” that can be understood by the device.

The outer borders of a picture, or its ratio of the height to width. The individual image on a roll of film. Also, to compose a picture.

The appearance or echoes of the silver crystals in film in the final negative or positive image. The larger the area of the grain in the film emulsion, the more sensitive the film is to light; the more sensitive it is to light the “faster” it is. Larger grains are manifest in the image as mottled or salt-and-pepper clumps of light and dark tones, usually apparent in very fast films on visual inspection, in slow films upon extreme magnification. Grain is most easily seen as non-uniform density in areas sharing the same tone (such as a gray sky.)

The range of tones, from bright white to pitch black that can be reproduced in a film and print.

The brightest parts of a scene that yield texture or image information. With slide film, it’s best to bias expose for the highlights, as overexposure of bright areas will yield a burnt-out look. A spectral highlight is pure light and will print as “paper” white.

The mount on the camera body in which electronic flashes are secured. Hot shoes usually contain electrical contact points that signal the flash to discharge when the shutter is fired.

The nearest point in the scene which is in focus when the lens is focused at infinity. This distance changes according to the focal length of the lens and the aperture at which it is set. Setting a lens at its hyperfocal distance maximizes the depth of field when infinity must be kept sharp.

The light that falls on a subject, rather than that which is reflected off it. Many handheld meters are of the incident light reading type. Incident readings are made from the subject with the meter pointed back at the camera.

On a camera lens distance scale, the distance greater than the last finite number, and beyond.

A prefix on film speed ratings that stands for International Standards Organization, the group that standardizes, among other things, the figures that define the relative speed of films.

A combination of shaped glasses and air spaces set in a specific arrangement within a barrel. Within the lens is a diaphragm that can be opened and closed to allow in specific amounts of light. This is controlled manually by a ring on the outside of the lens barrel, or electronically via pins in the coupling ring that mounts the lens to the camera. Lenses have two primary functions: one is to focus light with as little distortion or aberration as possible on to film or sensor. Focusing is accomplished by changing the relationship of the elements in the lens to the film plane. The other function is to control the amount of light hitting the film by use of its aperture. Autofocusing lenses may contain small motors for racking the lens back and forth in response to changes in focus.

Another word for close-up photography, but specifically referring to taking pictures at or near life-size. Can be defined as a ratio; for example, a 1:2 ratio means that the image on film is half-life-size of the object in nature.

An exposure “mode” where the exposure system recommends a setting that is then made by the photographer by selecting aperture and shutter speeds manually. The booklet one doesn’t read before using a piece of equipment.

A way of doing things. Exposure modes are pre-programmed, user-selectable ways of controlling the readings from the exposure system to meet certain subject or picture conditions. These include aperture-priority mode, shutter-priority mode, program-depth mode, etc. Autofocusing modes allow a choice of how the camera/lens will go about autofocusing.

In lenses, a specific set of pins and cams that couple a particular lens to a particular camera body. For photographs, a way of protecting the photograph and giving it a rigid support.

An image where the tones (recorded brightness values) and, with color film, the colors are reverse of those in the scene. When printed, the negative becomes “positive.”

In exposure, when too much lighting strikes the film for a proper rendition of the scene. Minor overexposure may cause a loss of details or texture in the scene highlights; severe overexposure will cause a serious deterioration of picture quality in color and black and white print film, and a complete loss of picture information with slide films.

A filter that transmits light waves vibrating in one direction, used to deepen blue sky with color film, tame contrast in very bright scenes, and to “see” through reflective surfaces, such as water and glass.

A meter that reads light reflected from the subject. All in-camera meters are of this type.

In color, a vividness, or intensity. Some films have more inherent color saturation than others. Saturation can be slightly increased by moderate film pushes, or by slight underexposure of certain slide films. Saturation can be increased in color negative film by moderate overexposure.

The perception that a picture, or parts of a picture are in focus. Also, the rendition of edges or tonal borders.

In a focal plane shutter, a set of curtains travels past the film gate and allows light to strike the film within a set period of time. A leaf shutter is located within the lens itself.

An element of exposure; the duration of time in which light is allowed to strike the film.

Or SLR. A type of camera that has a movable mirror behind the lens and a ground glass for viewing the image. Film sits behind the mirror assembly, which swings out of the way when an exposure is made. “Single-lens” distinguishes it from TLR, or twin-lens-reflex cameras, where separate lenses are used for viewing and taking.

With a shutter, the duration of time in which light strikes the film. With film, the sensitivity to light. With a lens, the maximum aperture. All can be described as either fast, medium, or slow speed.

The timing of the firing of the flash to coincide with the opening of the shutter so that the maximum light from that flash records on the film.

A generic name for a lens with a focal length of higher than 50mm and an angle of view less than 45 degrees (with 35mm format.) A moderate telephoto might be in the 80mm class; a medium telephoto in the 135mm grouping; while a long-range, or extreme telephoto might have a 300mm or higher focal length.

A three-legged device with a platform or head for attaching the camera, used to steady the camera during exposure. It is most useful for exposures longer than 1/30 second, or when a constant framing must be maintained throughout a series of shots.

Or Through-The-Lens metering. A flash autoexposure mode that measures light as it reflects off the film plane is referred to as OTF-TTL (off-the-film plane TTL.)

Failure to expose correctly because not enough light has struck the film or sensor to faithfully render the color and brightness values. Underexposed pictures are dark; the more the underexposure the darker they become. Color also suffers when film is underexposed, although a slight amount of underexposure can be used to increase color saturation in certain color slide films.

A clear, colorless filter that stops most ultraviolet rays from recording on film. Handy for shooting distant landscape shots, as it eliminates the bluish haze that might otherwise veil the picture.

The viewing screen in an SLR on which composition takes place; viewfinders may also contain various guides to exposure, focus, and flash-readiness. In all senses, the control panel from work is done.

A lens that offers a wide angle of view, usually in the 35 to 24mm focal length range. Ultra-wide-angle lenses range from 20mm to 8mm. Wide-angle lenses also allow use of very deep zones of focus.

A lens on which the focal length can be varied, as opposed to a fixed focal length lens. Zooms come in various focal length ranges, such as 35 to 105mm; all focal lengths including and within this range can be utilized.