A

AE-L (Automatic Exposure Lock)

Auto exposure Lock. Metering feature that used to hold the exposure setting when used in the automatic mode. Used most commonly in situation where off centering of the subject in composition and wish to retain the exposure setting of the subject OR where the level of exposure reading both the subject of interest and the background exposure reading is different eg. back lighting. Used to hold an automatically controlled shutter speed and/or aperture. Recommended when the photographer wants to control an exposure based on a scene's particular brightness area with Center Weighted or Spot Metering.

Aperture

Lens opening. The hole or opening formed by the metal leaf diaphragm inside the lens or the opening in a camera lens through which light passes to expose the film. The size of aperture is either fixed or adjustable. Aperture size is usually calibrated in f- numbers-the larger the number, the smaller the lens opening. Aperture affects depth of field, the smaller the aperture, the greater is the zone of sharpness, the bigger the aperture, the zone of sharpness is reduced. The hole or opening formed by the metal leaf diaphragm inside the lens; controls amount of light and depth of field, prevents vignetting and reduces lens aberrations; the size of the aperture is indicated by its f-number, i.e., the ratio of the diameter of the opening to the focal length of the lens; a large aperture is indicated by a small numerical f-number.

Aperture Priority

An exposure mode on an automatic or autofocus camera that lets you set the aperture while the camera sets the shutter speed for proper exposure. If you change the aperture, or the light level changes, the shutter speed changes automatically. Apart from the sport or action arena, aperture priority is the most common & effective automatic preference in photography. It can also explained as automatic exposure system in which the lens aperture is set by the photographer, and the camera sets the shutter speed. Can be used in the stop-down mode with any lens that does not interfere with the metering system.

Aspect Ratio

The ratio of width to height in photographic prints - 2:3 in 35 mm pictures to produce photographs most commonly measuring 3.5 x 5 inches or 4 x 6 inches; Advanced Photo System cameras deliver three aspect ratios as selected by the user.

Autofocus (AF)

System by which the camera lens (most popular) or the camera body (only available in Contax AX) automatically focuses the image of a selected part of the picture subject. The autofocus camera revolution first popularised with the launch of Minolta's Maxxium. Currently, most current SLRs are autofocus based.

AF-I & AF-S lenses

Nikon's new series of AF lenses, involves the intergration of coreless motors into their super telephoto lenses. This gives these lenses quick, ultra quiet autofocus operations. While the AF-S lenses housing a silent wave motor for even quicker and quiet operations than the AF-I lenses, which was being in the stage of being replaced by the newer series.

AV

The Aperture value, usually refer to aperture settings.

B

Backlighting

Light coming from behind the subject, toward the camera lens, so that the subject stands out vividly against the background. Sometimes produces a silhouette effect. Always use something (a hand, a lens shade to avoid the light falls onto the lens - to avoid lens flares).

C

Candid Pictures

Unposed pictures of people, often taken without the subject's knowledge. These usually appear more natural and relaxed than posed pictures.

Close-Up Lens

A lens attachment placed in front of a camera lens to permit taking pictures at a closer distance than the camera lens alone will allow.

Coated Lens

A lens covered with a very thin layer of transparent material that reduces the amount of light reflected by the surface of the lens. A coated lens is faster (transmits more light) than an uncoated lens.

Color Balance

How a color film reproduces the colors of a scene. Color films are made to be exposed by light of a certain color quality such as daylight or tungsten. Color balance also refers to the reproduction of colors in color prints, which can be altered during the printing process.

Colour temperature.

Description of the colour of a light-source by comparing it with the colour of light emitted by a (theoretical) perfect radiator at a particular temperature expressed in kelvins (K). Thus "photographic daylight" has a colour temperature of about 5500K. Photographic tungsten lights have colour temperatures of either 3400K or 3200K depending on their construction.

Composition

The pleasing arrangement of the elements within a scene-the main subject, the foreground and background, and supporting subjects.

Contrast

The range of difference in the light to dark areas of a negative, print, or slide (also called density); the brightness range of a subject or the scene lighting. It may be also explained as tonal difference. More often used to compare original and reproduction. A negative may be said to be contrasty if it shows fewer, more widely spaced tones than in the original.

Or another way to explain, a difference in visual brilliance between one part of the image and another; without contrast, there would be no such thing as a visible image; a line in a photograph is visible only because it is either darker or lighter in tone than the background; every distinguishable part of the image is the result of a contrast in tonal values.

Coma

A lens aberration restricted to off axis image points; the inability of a lens to render point sources of light near the edges of the frame as circular; the points of light appear as comet-shaped blurs (hence the name coma) with the tails flaring toward the center of the image; this aberration is very difficult to eliminate in wideangle lenses with large maximum apertures; improves by stopping down the lens.

Cropping

Printing only part of the image that is in the negative or slide, usually for a more pleasing composition, in medium format, esp the 6 x 6, some form of cropping is necessary for publishing on A4 magazine format. May also refer to the framing of the scene in the viewfinder.

D

Definition

The clarity of detail in a photograph.

Delayed action.

Mechanism delaying the opening of the shutter for some seconds after the release has been operated. Also known as self-timer.

Density

The blackness of an area in a negative or print that determines the amount of light that will pass through it or reflect from it. Sometimes referred to as contrast.

Depth of Field (DoF)

The zone of acceptable sharpness in front of and behind the subject on which the lens is focused; extends approx. one-third in front of and two thirds behind the in-focus subject; dependent on three factors: aperture, focal length, and focused distance; the wider the aperture, the longer the focal length, and the closer the focused distance, the less the depth of field, and vice versa; in comparison to a normal lens, wideangle lenses have inherently more depth of field at each f-number and telephoto lenses have less.

Since this element is very important, another simpler way to explain is the amount of distance between the nearest and farthest objects that appear in acceptably sharp focus in a photograph. Depth of field depends on the lens opening, the focal length of the lens, and the distance from the lens to the subject or can explain as in simpler term as the zone of sharpest focus in front of, behind, and around the subject on which the lens is focused; can be previewed in the camera - very handy for critical work.

Depth of Focus

The distance range over which the film could be shifted at the film plane inside the camera and still have the subject appear in sharp focus; often misused to mean depth of field. Also see "depth of field" section.

E

ED

Extra Low dispersion - usually refer to glass type. Glass with ED properties indicating special rare earth glass or special formulated glass that limiting or correcting of light rays passing through the lens elements to achieve all spectrum of colours to falls on the same plane of focus - especially the Red and Blue spectrum and is usually more apply to longer focal length lenses where the problem is more serious. First popularised by Nikon's Nikkor lens line - with a gold lining in the front part of the lens. Pentax, Olympus use the same name as Nikon. Canon's version is called "LD" - with red lining and usually their lenses are white in color. While Minolta uses APO. Independent lens makers, like Tamron, uses LD, Sigma uses APO, Tokina's version is SD APO; all these trade names are basically performing the same functions. Also please refer to "apodchhromatic" . Check Nikon's terms page for more.

Effective aperture.

The diameter of the bundle of light rays striking the first lens element that actually pass through the lens at any given diaphragm setting.

Electronic flash.

Light source based on electrical discharge across two electrodes in a gas-filled tube. Usually designed to provide light approximating to daylight. It is often regarded as artificial light souce in the dark. Electronic flash requires a high voltage, usually obtained from batteries through a voltage-multiplying circuit. It discharges a brief, intense burst of light, usually used where the lighting on the scene is inadequate for picture-taking. They are generally considered to have the same photographic effect as daylight. Most flash will correct the color temperature back to 5000 kelvin - the daylight color. You can play around with filters mounting on the flash head for some specific effects or alter the color if necessary. Modern flash has multiple TTL flash exposure control functions and even extend to autofocus control. Some specialized flash are high speed repeating flash which can use for strobocopic effect, UV-flash for ultra violet light photography etc.

EV

Exposure value. Method of quantifying scene brightness. Most of these value apply to metering cells, how high or low eg. a metering that can handles from EV1-EV21 means a metering system that can measure brightness level from just above the light level of a candle light to a brightly sunlight scene on a beach. Camera metering can handle more weakly on a spot meter than, say, a center weighted average metering system. EV is commonly used in black & White photographic process. At ISO 100, the combination of a one-second shutter speed and an aperture of F1.4 is defined as EV1. The camera may be used only within the EV range of the exposure meter. For example, the exposure metering range s from EV0 to EV20 can be used on a camera, means the camera's meter can handle broader range of exposure latitude.

Exposure

The quantity of light allowed to act on a photographic material; a product of the intensity (controlled by the lens opening) and the duration (controlled by the shutter speed or enlarging time) of light striking the film or paper. The act of allowing light to reach the light-sensitive emulsion of the photographic material. Also refers to the amount (duration and intensity) of light which reaches the film.

F

Filter

A colored piece of glass or other transparent material used over the lens to emphasize, eliminate, or change the color or density (ND) of the entire scene or certain areas within a scene. Also see "colour temperature", "UV". Technically, it explained as a piece of material which restricts the transmission of radiation. Generally coloured to absorb light of certain colours. Can be used over light sources or over the camera lens. Camera lens filters are usually glass either dyed or sandwiching a piece of gelatin in a screw-in filter holder.

Finder

Also known as viewfinder and projected frame. A viewing device on a camera to show the subject area that will be recorded on the film.

Fisheye lens.

Ultra-wide angle lens giving 180 angle of view. Basically produces a circular image on 35 mm, 5-9 mm lenses showing whole image, 15-17 mm lenses giving a rectangular image fitting just inside the circle, thus representing 180 across the diagonal.

Fixed-Focus

Describes a non-adjustable camera lens, set for a fixed subject distance.

Fixed-Focus Lens

A lens that has been focused in a fixed position by the manufacturer. The user does not have to adjust the focus of this lens, applies on most entry or disposable cameras.

Flash

The artificial light souce in the dark. Electronic flash requires a high voltage, usually obtained from batteries through a voltage-multiplying circuit. It has a brief, intense burst of light, usually used where the lighting on the scene is inadequate for picture-taking. They are generally considered to have the same photographic effect as daylight. Most flash will correct the color temperature back to 5000 kelvin - the daylight color. You can play around with filters mounting on the flash head for some specific effects or alter the color if necessary. Modern flash has multiple TTL flash exposure control functions and even extend to autofocus control. Some specialized flash are high speed repeating flash which can use for strobocopic effect, UV-flash for ultra violet light photography etc.

Flash Memory Card

A storage medium that uses by most digital cameras. It resembles film in conventional photography. We have an detailed article relating to this.

Flare

An overall decrease in contrast caused by light being reflected off, instead of transmitted through, a lens surface; controllable through the use of multilayer coating of individual lens elements in a lens; aggravated by unclean lens surfaces on front and rear lens elements or filters.

Flat

Too low in contrast. The range in density in a negative or print is too short or in some cases, reflecting the low resolution produced by a low quality lens.

F-Number

A number that indicates the size of the lens opening on an adjustable camera. The common f-numbers are f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, and f/22. The larger the f-number, the smaller the lens opening. In this series, f/1.4 is the largest lens opening and f/22 is the smallest. Also called f-stops, they work in conjunction with shutter speeds to indicate exposure settings. Also can be explained as numerical expression of the relative aperture of a lens at its different stops; equal to the focal length divided by the effective aperture of the lens opening and written in various forms, such as f/8, f8, 1: 8, etc.; each f-number is 1.4 times larger than the preceding one; each number indicates a halving or doubling of the amount of light allowed to pass through the lens; the next higher numbered f-number sign)fies an aperture which lets in exactly onehalf as much light, and the next lower number, twice as much light, i.e., f/11 lets in half as much light as f/8, while f/5.6 lets in twice as much; all lenses stopped down to the same f-number produce images of equal illumination (apart from differences due to varying reflection losses); therefore, for a given shutter speed, a given fnumber always corresponds to the same exposure.

f/stop

A fraction which indicates the actual diameter of the aperture: the "f" represents the lens focal length, the slash means "divided by," and the word "stop" is a particular f-number; for example, with a 50mm f/1.4 lens, the actual diameter of its maximum aperture is 50mm divided by 1.4 or 35.7mm; at f/2, the diameter becomes 50mm/2 or 25mm; at f/2.8, the aperture is 50mm/2.8 or 17.9mm across; as the numerical value of the f/stop increases, the aperture decreases in size.

Focal Length

The distance between the film and the optical center of the lens when the lens is focused on infinity. The focal length of the lens on most adjustable cameras is marked in millimetres on the lens mount. The distance from the principal point to the focal point. In 35mm-format cameras, lenses with a focal length of approx. 50mm are called normal or standard lenses. Lenses with a focal length less than approx. 35mm are called wide angle lenses, and lenses with a focal length more than approx. 85mm are called telephoto lenses. Lenses which allow the user to continuously vary the focal length without changing focus are called zoom lenses .

Focus

Adjustment of the distance setting on a lens to define the subject sharply. Generally, the act of adjusting a lens to produce a sharp image. In a camera, this is effected by moving the lens bodily towards or away from the film or by moving the front part of the lens towards or away from the rear part, thus altering its focal length.

Focus Range

The range within which a camera is able to focus on the selected picture subject - 4 feet to infinity - for example.

Focus-Priority for autofocus

Shutter cannot be released until the subject s in focus. For situations when an in-focus subject s important. With the F5 camera body, Focus-Priority s given to Single Servo AF mode while Release-Priority is g iven to Continuous Servo AF. Using Custom Setti ing, however, you can change the priority to Release-Priority Single Servo AF or Focus-Priority Continuous Servo AF.

Focus Tracking

Enables the camera to analyze the speed of the movi ing subject according to the focus data detected, and to obtain correct focus by anticipating the subject's position and driving the lens to that position&emdash;at the exact moment of exposure, basically a Nikon's and Canon's feature. Currently, Nikon lead the pack in this tecnology with the F5, the fastest among all.

fps

Frames per second. Used to describe how many frames can the motor drive or winder can handle automatically on winding per second consequently. Also apply to areas like video, animations, movie cameras


G

Ghost images

Bright spots of light, often taking the shape of the aperture, which appear in the camera viewfinder or in the final photograph when a lens is pointed at a bright light like the sun; controllable through the use of multilayer coating of the lens elements.

Grain.

Minute metallic silver deposit, forming in quantity the photographic image. The individual grain is never visible, even in an enlargement, but the random nature of their distribution in the emulsion causes over-lapping, or clumping, which can lead to graininess in the final image. Also cross check with below for graininess.

H

High Contrast

A wide range of density in a print or negative.

Highlights

Small, very bright part of image or object. Highlights should generally be pure white, although the term is sometimes used to describe the lightest tones of a picture, which, in that case, may need to contain some detail.

I

Iris.

Strictly, iris diaphragm. Device consisting of thin overlapping metal leaves pivoting outwards to form a circular opening of variable size to control light transmission through a lens.

ISO Speed

The international standard for representing film sensitivity. The emulsion speed (sensitivity) of the film as determined by the standards of the International Standards Organization. In these standards, both arithmetic (ASA) and logarithmic (DIN) speed values are expressed in a single ISO term. For example, a film with a speed of ISO 100/21° would have a speed of ASA 100 or 21 DIN. The higher the number, the greater the sensitivity, and vice versa. A film speed of ISO 200 is twice as sensitive as ISO 100, and half that of ISO 400 film.

IF (Internal Focusing System)

Available on some of Nikon's lenses: branded Nikkor


L

Lens Shade

A collar or hood at the front of a lens that keeps unwanted light from striking the lens and causing image flare. May be attached or detachable, and should be sized to the particular lens to avoid vignetting.

Lens Speed

The largest lens opening (smallest f-number) at which a lens can be set. A fast lens transmits more light and has a larger opening than a slow lens. Determined by the maximum aperture of the lens in relation to its focal length; the "speed" of a lens is relative: a 400 mm lens with a maximum aperture of f/3.5 is considered extremely fast, while a 28mm f/3.5 lens is thought to be relatively slow.


M

Macro Lens

A lens that provides continuous focusing from infinity to extreme close-ups, often to a reproduction ratio of 1:2 (half life-size) or 1:1 (life-size). Nikon's version for their "macro" is "micro", eg. 105mm F2.8 Micro-Nikkor.

Micro lens

A lens for close-up photography; designed to focus continuously from infinity down to a reproduction ratio of 1: 2, or with a matched extension ring or teleconverter down to 1: 1; available in normal or telephoto focal lengths to provide a variety of free working distances; with the exception of Nikon, this type of lens is called a "Micro Nikkor" lens. Also see above, Macro or Makro (Usually for German origin lenses)..

Macro photography

The process of taking photographs of small objects with regular photographic lenses at reproduction ratios of 1X or greater; also referred to as "photomacrography. "

Manual

User selects both shutter speed and aperture, following or ignoring the meter's recommendations to achieve the desired exposure.

O

Overexposure

A condition in which too much light reaches the film, producing a dense negative or a very bright/light print or slide.


P

Panning

Moving the camera so that the image of a moving object remains in the same relative position in the viewfinder as you take a picture. The eventual effect creates a strong sense of movement.

Perspective

The rendition of apparent space in a flat photograph, i.e., how far the foreground and background appear to be separated from each other; determined by only one factor: the camera-to-subject distance; if objects appear in their normal size relations, the perspective is considered "normal"; if the foreground objects are much larger than the ones in the background, the perspective is considered "exaggerated"; when there is little difference in size between foreground and background, we say the perspective looks "compressed."

Plane.

Level surface. Used in photography chiefly in respect to focal plane, an imaginary level surface perpendicular to the lens axis in which the lens is intended to form an image. When the camera is loaded the focal plane is occupied by the film surface.

Polarising Screen (Filter)

A filter that transmits light travelling in one plane while absorbing light travelling in other planes. When placed on a camera lens or on light sources, it can eliminate undesirable reflections from a subject such as water, glass, or other objects with shiny surfaces. This filter also darkens blue sky.

Processing

Developing, fixing, and washing exposed photographic film or paper to produce either a negative image or a positive image. Also used on digital images using photo manipulation programs such as photoshop and Lightroom

Program Exposure

An exposure mode on an automatic or autofocus camera that automatically sets both the aperture and the shutter speed for proper exposure.

Programmed Auto:

Camera sets both shutter speed and aperture for correct exposure.

Push Processing

Increasing the development time of a film to increase its effective speed (raising the ISO number for initial exposure ) for low-light situations; forced development.

S

Saturation

An attribute of perceived color, or the percentage of hue in a color. Saturated colors are called vivid, strong, or deep. Desaturated colors are called dull, weak, or washed out.

Scale.

Focusing method consisting of set of marks to indicate distances at which a lens is focused. May be engraved around the lens barrel, on the focusing control or on the camera body.

Selective Focus

Choosing a lens opening that produces a shallow depth of field. Usually this is used to isolate a subject by causing most other elements in the scene to be blurred.

Sensitivity.

Expression of the nature of a photographic emulsion's response to light. Can be concerned with degree of sensitivity as expressed by film speed or response to light of various colours (spectral sensitivity).

Sharpness

A term used to describe the ability of a lens to render fine detail clearly; dependent on the contrast and resolution of a lens and varies with the f/stop; in general, a lens is sharpest at the middle apertures. Also technically can be explained as clarity of the photographic image in terms of focus and contrast. Largely subjective but can be measured to some extent by assessing adjacency effects, i.e. the abruptness of the change in density between adjoining areas of different tone value.

Shutter

Blades, a curtain, plate, or some other movable cover in a camera that controls the time during which light reaches the film.

Shutter Priority

An exposure mode on an automatic or autofocus camera that lets you select the desired shutter speed; the camera sets the aperture for proper exposure. If you change the shutter speed, or the light level changes, the camera adjusts the aperture automatically.

T

Telephoto Lens

A lens that makes a subject appear larger on film than does a normal lens at the same camera-to-subject distance. A telephoto lens has a longer focal length and narrower field of view than a normal lens and have a shallower depth of field than wide angle lenses. But it can do isolation of subject and have a longer reach without going near to the subject. Life can be very difficult in sports and wildlife photography. Telephoto lens whose focal length is longer than the diagonal of the film frame; in 35mm photography, lenses longer than 50-5Bmm; also referred to as a "long" lens.

Time Exposure

A comparatively long exposure made in seconds or minutes.

Tripod

A three-legged supporting stand used to hold the camera steady. Especially useful when using slow shutter speeds and/or telephoto lenses. Another is the monopod, single leg tripod.

T/S

The tilt and shift lens, Canon's version of the PC (perspective control) lens.


U

Ultra-wide angle lens.

Extra-wide angle lens, usually those with an angle of view greater than 90°. For 35 mm cameras the description usually applies to lenses of shorter focal length than about 24 mm.

Underexposure

A condition in which too little light reaches the film, producing a thin negative, a dark slide, or a muddy-looking print.

Unipod

Also refer as monopod.A one-legged support used to hold the camera steady. Also see "tripod".

V

Variable focus lens.

Lens of which the focal length can be continuously varied between set limits. The lens must be refocused with each change in focal length.

Vignetting

Underexposure of image corners produced deliberately by shading or unintentionally by inappropriate equipment, such as unsuitable lens hood or badly designed lens. A common fault of wide-angle lenses, owing to reflection cut-off, etc. of some of the very oblique rays. May be caused in some long-focus lenses by the length of the lens barrel.

W

Wide-Angle Lens

A lens that has a shorter focal length and a wider field of view (includes more subject area) than a normal lens.Also can explained as a lens whose focal length is shorter than the diagonal of the film frame; in 35mm photography, lenses shorter than 50mm; also referred to as a "short" lens.

Z

Zoom Lens

A lens in which you adjust the focal length over a wide range of focal lengths. Subsituting lenses of many focal lengths. Zoom lenses whose focal length is continuously variable over a certain range without a change in focus; its focal length is changed by operating a separate zoom or a combination focusing/zoom ring; difficult type of lens to design and manufacture, very useful for the photographer on a budget or one who likes to travel light.

Source: http://www.mir.com.my/rb/photography...ry/terms_a.htm