GLOSSARY

ANGLE OF INCIDENCE - The angle at which the light striking on a surface called the incident light strikes is called the “angle of incidence”.

APERTURE - A circle-shaped opening in a lens (a hole, really) through which light passes to strike the film. The aperture is usually adjustable to be made wider or narrower allowing in more or less light. The size of the aperture is expressed as an '-number, like '/8 or '/11.

ASPECT RATIO – Length to width ratio of a picture is its aspect ratio. For example, 35mm film has an aspect ratio of 3:2. Most digital cameras have an aspect ratio of 4:3.

BULB - A shutter speed dial setting which indicates that the shutter will remain open as long as the shutter release button is kept pressed - also known as the “B setting”, this mode is used for time exposures.

BACK-LIGHTING – When the light is directed at the subject from behind the subject, it is called Back-Lighting.

CAMERA SHAKE - Slight movement of the camera when the exposure is being made.

CHARGE COUPLE DEVICE (CCD) - In a digital SLR, the chip on which tiny dots of light and color called pixels are recorded is called a CCD.

CMYK - An acronym for the ink colors Cyan (blue), Magenta (red), Yellow and Black used in four-color process printing.

CONTRAST - The range of difference between highlights and shadow areas in a picture. It can also be defined as the amount of brightness in a picture or scene.

DARKROOM - A room where light sensitive materials such as a film can be easily handled because of complete absence of light in the room. Exposure to light may spoil the film and hence a darkroom is necessity for developing the film.

DAYLIGHT FILM – color films are designed to give correct color balance in particular times of the day according to the presence of sunlight. So the film which is specially designed to give accurate color balance in day light is a daylight film.

DEPTH OF FIELD - The range of distance in a scene that appears to be in focus in an image and range of area in which the colors are sharp enough is termed as depth of field. It is controlled by the lens aperture.

DIAPHRAGM – it is a ring with an adjustable hole in the center that controls the amount of light entering the camera. The size of the hole or aperture permits more or less light to pass through the lens and then strike the film or sensors.

DIFFUSED LIGHT– A less sharp light than direct light which is scattered and spread out is called diffused light. This type of light is helpful in taking less sharply defined pictures and pictures that are of low contrast.

DODGING - Sometimes a portion of light is blocked while printing a photograph so that a particular area of the print is lighter. This technique is called Dodging.

DOUBLE-EXPOSURE – When the same subject is wanted twice in a picture, the film frame is exposed twice. This type of exposure is called Double-Exposure.

EXPOSURE – The process during which light is allowed to enter the camera and strike the surface of the film is called exposure. A proper exposure or the right amount of light striking the surface of the film gives satisfactory results to the photographer.

f-NUMBER - (ƒ-number) A number that expresses a lens’ light-transmitting ability - i.e. the size of the lens opening. Usually found on the barrel of a lens, f-numbers indicate the size of the aperture in relation to the focal length of the lens. A smaller number indicates a larger lens diameter. ƒ/1.4 signifies that the focal length of the lens is 1.4 times as great as the diameter. All lenses set at the same f-number transmit the same amount of light.

FILM – Very thin, flexible strips made up of cellulose nitrate or cellulose acetate used in a camera for the purpose of recording the image is called a film. These are coated with light sensitive emulsions in order to take photographs.

FILM SPEED – this is measured in ISO. Higher ISO means that the film is more sensitive to light and needs lesser exposure time or less amount of light for perfect exposure. Whereas a lesser amount requires proper day light and higher timed exposure for a clear and sharp image. Hence ISO-100 can be used for pictures to be shot at day time while an ISO-400 may be needed for a good picture to be shit at night.

FIXER – It is the chemical solution used for fixation of photographs.

FLASH - A brief and sudden burst of white light from a flash bulb used to provide the object an artificial light for a clear and crisp picture. Some cameras may have in-built flash like an ordinary point and shoot camera while some may have it as an added on feature which can be used only when required as in the case of SLR camera.

FOCAL LENGTH – This is the distance between the focal point of the lens of the camera and the film. It is measured in mm and is always written on the front side of the lens.

FOCUS – A well defined, sharp and clear picture is said to be in focus. The lens can be adjusted to focus the image by setting the distance between the lens and the image.

HYPO – A chemical bath used to remove any light-sensitive, silver halide crystals that have not been acted upon while exposure to light is termed as a hypo bath. It contains various chemicals including sodium thio-sulphate and water. This bath stabilizes the negative so that it no more reacts with light.

INCIDENT LIGHT – The light falling on a surface is called incident light.

LENS - A “lens” is a single piece of glass (or other transparent substance) having one or more curved surfaces. It is basically used for changing the convergence of light rays. A photographic lens is more accurately and technically called an “objective”. Here it is an optical device which has a combination of lenses. This lens forms an image on the focal plane through the light it receives from an object. A camera lens collects and focuses rays of light to form an image on film.

NEGATIVE – A negative is such an image on the photographic film which is used for developing the final photographs. In this, the brightness values are reversed. The dark areas in the original picture are light in the negative and vice-versa.

PARALLAX – There is always a slight difference between what is seen through the viewfinder and what the camera records on film. This is termed as parallax. In case of a SLR, it is not much but as far as a point and shoot viewfinder is concerned, parallax is quite high.

PENTAPRISM – A five-sided prism in SLR cameras which renders a correctly-oriented view on the focusing screen.

RESOLVING POWER – This explains the fineness of a picture. It is decided by either the lens or the film or both together. Higher the resolving power, better is the picture quality.

SHARPNESS - An image’s degree of clarity in terms of focus and contrast.

SHUTTER - A movable cover for an opening. In photography, that opening is the lens - more specifically, the aperture. The shutter blocks the passage of light traveling through the lens to the film when it is closed, and allows light to reach the film when it is open. Shutters are composed of blades, a curtain, a plate or another movable cover. They control the amount of time that light is allowed to pass through the opening to reach the film.

SHUTTER SPEED – It is the speed of the shutter which to an extent decides the amount of light that will be entering the camera for exposure. Higher the shutter speed, less is the amount light allowed to enter the camera.

TRIPOD – This is a pole on which the camera can be attached for clicking pictures which need timed exposures or for which the shutter speed is very slow. A tripod stand reduces the chances of a camera shake by hand while taking a photograph. This pole has three legs and is generally made of steel and plastic.

UNDEREXPOSURE – Lack of an appropriate amount of light while exposing the film which results in an unclear image is called underexposure. An underexposed image may result in unclear areas in the photograph with featureless objects that are in the dark areas.

ZOOM LENS – A lens which allows itself to change its focal length with the help of shifting of the elements inside it is called a zoom lens. As this lens has various focal lengths for use at the same time, it is also known as a “variable focus lens”.