ABC
Auto Backlighting Control, metering feature that automatically recognises a subject in back lighting condition and increase the exposure to compensate.
Accessory Shoes - also often called "Hot Shoe". The early flash types were simple metal brackets. To install a flash unit, you just slide the mounting foot of the flash into the accessory shoe. No electrical connection is made between camera and flash - it's just a simple and convenient way to attach the flash unit to the camera. Subsequent accessory shoes have been built as part of the camera and usually reat on top of the camera's pentaprism; others are separate items that you mount on the camera body when you need them. Some like the Nikon early professional camera has special dedicated which was designed around the rewind knob.
Aberration.
Failing in the ability of a lens to produce a true image. There are many forms of aberration and the lens designer can often correct some only by allowing others to remain. Generally, the more expensive the lens, the less its aberrations (More attention to optical quality). While no single lens is called a 'perfect lens'. The "ideal" lense would reproduce a subject in a faithful, clearly defined image on film. Aberrations, which can be divided into six basic faults, affect the Ideal performance in an optical system.
a) Spherical aberration. Basically, a beam of light passing through a lens parallel to the optical axis converges to form 3 focused image on the film. Spherical aberration is the term for an optical fault caused by the spherical form of a lense that produces different focus points along the axis for central and marginal rays.
b) Curvature of field. This optical defect causes points on an object plane perpendicular to the lens axis to focus on a curved surface rather than a plane.
c) Astigmatism. Rays of light from a single point of an object which is not on the axis of a lense fail to meet in a single focus thus causing the image of a point to be drawn out into two sharp lines, one radial to the optical axis and another perpendicular to this line, in two different planes near the curvature of field.
d) Coma. This optical defect causes the image of an off-axis point of light to appear as a comet-shaped blur of light. Coma, as well as curvature of field and astigmatism, degenerate the image forming ability of the lense at the rims of the picture.
e) Distortion. Even if the first four aberrations were totally eliminated, images could result that still have a distorted appearance. For an example, an rectangle may appear as a barrel or pin cushion-shaped object.
f) Chromatic aberration. This aberration is caused by light rays of different wavelengths coming to focus at different distances from the lense. Blue will focus at the shortest distance and red at the greatest distance. Since the natural rays of light are a mixture of colors, each aberration will give a different value corresponding to each color thus producing blurred images.
Adjustable Camera
Commonly called the manual camera. A camera with manually adjustable settings for distance, lens openings, and shutter speeds. eg Nikon FM series, Carl Zeiss S2, Pentax K1000, Yashica FX-3 super etc.
Adjustable-Focus Lens
A lens that has adjustable distance settings.
Advanced Photo System
A new standard in consumer photography developed by Kodak and four other System Developing Companies - Canon, Fuji, Minolta and Nikon - based on a new film format and innovative film, camera and photofinishing technologies. Generally, APS cameras are more compact in size, weight and enbodied most of the latest and most advance technologies available. There are options in various sizes of print out and it will even provide a thumbnail prints (Contact sheet) for you to select or preview prior to actual printing. There have a different series of lenses and some of the 35mm format AF lenses can even be shared (With limitation or effective focal length will increased). You can say, it is a different system camera all together. So much for the brighter side, but there are drawbacks as well and it is not that economical as I originally thought it supposed to be.
AE (Automatic Exposure)
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.
Agitation
Keeping the developer, stop bath, or fixer in a gentle, uniform motion while processing film or paper. Agitation helps to speed and achieve even development and prevent spotting or staining.
Alphabetical Coding:
Some early lenses such as Nikon and Olympus uses some alphabetical coding to illustratre the composition of their lenses. Fora na exmaple, each ZUIKO Lens is described with an alphabetical prefix and suffix such as F . ZUlK0 AUTO-S, AUTO-T, etc. The prefix represents the number of elements in a lens in alphabetical order. For an instance, "A"=1 element, "B"=2 elements, "D"=4 elements, and so forth. "AUTO" signifies automatic diaphragm. The suffix represents the type of lense: "S": Standard, "W"=Wide Angle and "T"=Telephoto. While another example:
U (Uns) for 1 lense element
B (Bini) for 2 elements
T (Tres) for 3 elements
Q (Quatour) for 4 elements
P (Pente) for 5 elements
H (Hex) for 6 elements
S (Septem) for 7 elements
0 (Octo) for 8 elements
N (Novem) for 9 elements
D (Decem) for 10 elements
Ambient Light
The available natural light completely surrounding a subject. Light already existing in an indoor or outdoor setting that is not caused by any illumination supplied by the photographer i.e. not by artificial light source.
Angle Of View
The area of a scene that a lens covers or sees. Angle of view is determined by the focal length of the lens. A wide-angle lens (short-focal-length) includes more of the scene-a wider angle of view-than a normal (normal-focal-length) or telephoto (long-focal-length) lens. Currently, the widest view available is 220 degree (achieved by Nikon's Nikkor 6mm F2.8 fisheye lens - 220 degree; while the narrowest is Nikon, 2000mm F11 Reflex Nikkor, only slightly over 1 degree of view. It can also be explained as the extent of the view taken in by a lens. For any particular film size, it varies with the focal length of the lens. Usually expressed on the diagonal of the image area. Basically, there are three types of angles which can be measured (based on horizontal, vertical and diagonals of the film frame), the lense must be designed to cover the widest angle in the diagonal direction. Thus, the angle of view is the angle between imaginary lines drawn from the opposite ends of the film plane to the second nodal point of the lense. All objects within this angle will be recorded by the lense on the film.
A-PEN
Annealed polyethylene naphthalate-a polyester material used as the base on Advanced Photo System film; thinner, stronger and flatter than the acetate base traditionally used in consumer photographic roll films.
APO
Apochromatic. Having the ability to bring all colours of the visible spectrum to a common plane of focus, within close tolerances, usually refer to a lens with such superior colour correction. Also refer to "ED", "LD", "SD", "UD".
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.
Aperture ring
A ring, located on the outside of the lens usually behind the focusing ring, which is linked mechanically to the diaphragm to control the size of the aperture; it is engraved with a set of numbers called f-numbers or f- stops.
Artificial light.
Light from a man-made source, usually restricted to studio photo lamp and domestic lighting. When used to describe film (also known as Type A or Type B) invariably means these types of lighting.
Aspherical lens
A lens whose curved surface does not conform to the shape of a sphere; lenses are usually ground or molded with spherical surfaces; because a spherical surface lens has difficulty in correcting distortion in ultra-wideangle lenses or coma in large-aperture lenses brought about by spherical aberration, an aspherical lens is used.
ASA
American Standards Association. Group that determining numerical ratings of speed for US made photosensitive products. eg films. In 1982, its role and its influence was narrow down by the establishment of the ISO (International Standards Organisation).
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.
ATA
ATA- This means the camera supports the electrical interface standard, defined by the PC Card Association (formerly PCMCIA), known as ATA (AT Attachment). This is the mobile computing equivalent of the IDE standard for desktop computers. Most computers have ATA support built-in. ATA is supported by most operating systems like Microsoft Windows 3.1, Windows '95, Windows CE, IBM OS/2, Apple System 7, etc. ATA is supported by most computer manufacturers including IBM, Compaq, Packard Bell, Dell, Gateway 2000, etc.
Auto Exposure Bracketing:
Auto Exposure Bracketing performs automatic exposure bracketing with varied shutter speed and/or aperture.
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.
Automatic Camera
A camera with a built-in exposure meter that automatically adjusts the lens opening, shutter speed, or both (program) for proper exposure.
Automatic iris.
Lens diaphragm which is controlled by a mechanism in the camera body coupled to the shutter release. The diaphragm closes to any preset value before the shutter opens and returns to the fully open position when the shutter closes.
AV
The Aperture value, usually refer to aperture settings.
Digital Photography
Capturing what is real and abstract in this digital world.
Saturday, December 27, 2008
Glossary of Photography Terms (B)
B (Bulb) Setting
A shutter-speed setting on an adjustable camera that allows for time exposures. When set on B, the shutter will stay open as long as the shutter release button remains depressed. Another similar option is the "T" setting, where it never drains the battery power on automatic camera body.
Background
The part of the scene the appears behind the principal subject of the picture. The sharpness of the background can be influenced by apertures and shuttle set. In the flash mode, bulb setting usually is set for absorbing more ambience light (background information), so the end result of the exposure won't be pitch dark.
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).
Back-Printing
Information printed on the back of a picture by the photofinisher. The system standard requires the printing of frame number, film cassette number and processing date automatically on the back of each Advanced Photo System print; may also include more detailed information, such as customized titles and time and date of picture-taking.
Barrel Distortion
Straight lines are bowed in at the edges of the picture frame re sembling the sides of a barrel; pres ent in small amounts in some wideangle or wideangle-zoom lenses, bu~ uncorrected in fisheye lenses.
Balance
Placement of colors, light and dark masses, or large and small objects in a picture to create harmony and equilibrium. Description applied to colour films to indicate their ability to produce acceptable colour response in various types of lighting. The films normally available are balanced for daylight (550~6000K photo lamps (3400K) or studio lamps (3200K).
Balanced Fill-Flash : A type of TTL auto flash operation which uses the camera's exposure meter to control ambient light exposure settings, integrated with flash exposure control. That is, flash output level is automatically compensated to balance with ambient light, resulting in a better exposure for both subject and background.
Balanced fill-flash operation :
A flash photography technique that balances flash illumination with the scene's ambient light. This automatic operation utilizes the some camera's Automatic Balanced Fill Flash System with TTL Multi Sensor and a compatible dedicated TTL Speedlight.
Bellows
The folding (accordion) portion in some cameras that connects the lens to the camera body (like the Mamiya RZ). Also a camera accessory that, when inserted between lens and camera body, extends the lens-to-film distance for close focusing or macro phtography. Some retains the automatic functions where some have to stopdown the lens for manual exposure reading.
Between-The-Lens Shutter
A shutter whose blades operate between two elements of the lens. Most medium format cameras like the Hasselblad have one family of lens with shuttle and another without. Most lenses in this family have a smaller maximum aperture than the other family.
Blowup
An enlargement; a print that is made larger than the negative or slide.
Bounce Lighting
Flash or tungsten light bounced off a reflector (such as the ceiling or walls) or attachment that fits on the flash (like the LumiQuest's Pocket Bouncer) to give the effect of natural or available light.
Bracket flash
Often called handle mount flash. It comprised of one arm of the L-shaped bracket extends under the camera body and uses the camera's tripod socket to mount the camera on the bracket. The vertical arm of the bracket serves as a handle and mounts a flash unit in an accessory shoe often on top of the handle portion, but there are other methods. Flash mounted in a bracket usually requires a separate electrical cord to make the electrical connection between camera body and flash unit.
Bracketing
Taking a series of photographs of the same subject at different exposures to insure the "correct" exposure; useful when shooting in situations where a normal metering reading is difficult to obtain. Taking additional pictures of the subject through a range of exposures-both lighter and darker-when unsure of the correct exposure.Some top cameras have provision for automatic bracketing, while manually you can bracket by the use of, say, adjust apertures or shuttle speeds setting or both, manually influent the ASA setting or even adjust the flash output power etc..
Burning-In
Basically, a darkroom process that gives additional exposure to part of the image projected on an enlarger easel to make that area of the print darker. This is accomplished after the basic exposure by extending the exposure time to allow additional image-forming light to strike the areas in the print you want to darken while holding back the image-forming light from the rest of the image. Sometimes called printing-in.
Bulb
Flashbulbs - A special flashbulb that can be used at certain shutter speeds is called "FP" where the initials stand for Focal Plane. Designed for use with focal-plane shutters these bulbs make a nearly uniform amount of light for a relatively long time. The idea is to turn on the light before the focal-plane shutter starts to open and keep the light on until the shutter is completely closed. Firing delay for flashbulbs is indicated by code letters: "F"- fast; "M"- medium; "MF" - mediurn fast; "S" - slow
A shutter-speed setting on an adjustable camera that allows for time exposures. When set on B, the shutter will stay open as long as the shutter release button remains depressed. Another similar option is the "T" setting, where it never drains the battery power on automatic camera body.
Background
The part of the scene the appears behind the principal subject of the picture. The sharpness of the background can be influenced by apertures and shuttle set. In the flash mode, bulb setting usually is set for absorbing more ambience light (background information), so the end result of the exposure won't be pitch dark.
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).
Back-Printing
Information printed on the back of a picture by the photofinisher. The system standard requires the printing of frame number, film cassette number and processing date automatically on the back of each Advanced Photo System print; may also include more detailed information, such as customized titles and time and date of picture-taking.
Barrel Distortion
Straight lines are bowed in at the edges of the picture frame re sembling the sides of a barrel; pres ent in small amounts in some wideangle or wideangle-zoom lenses, bu~ uncorrected in fisheye lenses.
Balance
Placement of colors, light and dark masses, or large and small objects in a picture to create harmony and equilibrium. Description applied to colour films to indicate their ability to produce acceptable colour response in various types of lighting. The films normally available are balanced for daylight (550~6000K photo lamps (3400K) or studio lamps (3200K).
Balanced Fill-Flash : A type of TTL auto flash operation which uses the camera's exposure meter to control ambient light exposure settings, integrated with flash exposure control. That is, flash output level is automatically compensated to balance with ambient light, resulting in a better exposure for both subject and background.
Balanced fill-flash operation :
A flash photography technique that balances flash illumination with the scene's ambient light. This automatic operation utilizes the some camera's Automatic Balanced Fill Flash System with TTL Multi Sensor and a compatible dedicated TTL Speedlight.
Bellows
The folding (accordion) portion in some cameras that connects the lens to the camera body (like the Mamiya RZ). Also a camera accessory that, when inserted between lens and camera body, extends the lens-to-film distance for close focusing or macro phtography. Some retains the automatic functions where some have to stopdown the lens for manual exposure reading.
Between-The-Lens Shutter
A shutter whose blades operate between two elements of the lens. Most medium format cameras like the Hasselblad have one family of lens with shuttle and another without. Most lenses in this family have a smaller maximum aperture than the other family.
Blowup
An enlargement; a print that is made larger than the negative or slide.
Bounce Lighting
Flash or tungsten light bounced off a reflector (such as the ceiling or walls) or attachment that fits on the flash (like the LumiQuest's Pocket Bouncer) to give the effect of natural or available light.
Bracket flash
Often called handle mount flash. It comprised of one arm of the L-shaped bracket extends under the camera body and uses the camera's tripod socket to mount the camera on the bracket. The vertical arm of the bracket serves as a handle and mounts a flash unit in an accessory shoe often on top of the handle portion, but there are other methods. Flash mounted in a bracket usually requires a separate electrical cord to make the electrical connection between camera body and flash unit.
Bracketing
Taking a series of photographs of the same subject at different exposures to insure the "correct" exposure; useful when shooting in situations where a normal metering reading is difficult to obtain. Taking additional pictures of the subject through a range of exposures-both lighter and darker-when unsure of the correct exposure.Some top cameras have provision for automatic bracketing, while manually you can bracket by the use of, say, adjust apertures or shuttle speeds setting or both, manually influent the ASA setting or even adjust the flash output power etc..
Burning-In
Basically, a darkroom process that gives additional exposure to part of the image projected on an enlarger easel to make that area of the print darker. This is accomplished after the basic exposure by extending the exposure time to allow additional image-forming light to strike the areas in the print you want to darken while holding back the image-forming light from the rest of the image. Sometimes called printing-in.
Bulb
Flashbulbs - A special flashbulb that can be used at certain shutter speeds is called "FP" where the initials stand for Focal Plane. Designed for use with focal-plane shutters these bulbs make a nearly uniform amount of light for a relatively long time. The idea is to turn on the light before the focal-plane shutter starts to open and keep the light on until the shutter is completely closed. Firing delay for flashbulbs is indicated by code letters: "F"- fast; "M"- medium; "MF" - mediurn fast; "S" - slow
Glossary of Photography Terms (C)
"C"-Format
CRC (Close Range Correction System): Check Nikon's terms page for more.
"Classic" format - one of the three selectable Advanced Photo System print formats; identical to the 2:3 aspect ratio used in 35 mm photography and suitable for most general-purpose shots.
Camera Angles
Various positions of the camera (high, medium, or low; and left, right, or straight on) with respect to the subject, each giving a different viewpoint, perspective or visual effect.
Camera shake.
Movement of camera caused by unsteady hold or support, vibration, etc., leading, particularly at slower shutter speeds, to a blurred image on the film. It is a major cause of un-sharp pictures, especially with long focus lenses.
Candid Pictures
Unposed pictures of people, often taken without the subject's knowledge. These usually appear more natural and relaxed than posed pictures.
Capacitor.
Electrical component once more commonly known as a condenser. Stores electrical energy supplied by a power source and can discharge it more rapidly than the source itself. Used in flash equipment, providing reliable bulb firing even from weak batteries, and supplying the surge needed for electronic flash tubes.
Cartridge
A lighttight, factory-loaded film container that can be placed in and removed from the camera in daylight. Some nature of film, like the infra red film, MUST not even try to load or unload film in any possible light existence, absolutely must be in total pitch dark condition to avoid fogging on film.
Cassette
Light-trapped film container used with 35 mm cameras.
Elliptically shaped film cassette designed especially for the Advanced Photo System that serves as the sealed, leaderless container for all System film whether unexposed, exposed or processed.
Cast.
Abnormal colouring of an image produced by departure from recommended exposure or processing conditions with a transparency film, or when making a colour print. Can also be caused by reflection within the subject as from a hat on to the face.
CCD
Electronic sensor used by all autofocus cameras, capable of detecting subject contrast; also an image-receiving device for video camera.
Cds
Cadmium Sulfide (Cell). A battery powered, current-modulating. light-sensing cell that was quite popular with lots of cameras exposure metering system and external metering devices. May be this extra will help, photo conductive material used in exposure meters as alternative to selenium-based or silicon blue photocells. Its electrical resistance decreases as the light falling on it increases. Cds meters use current from an external power source, such as a battery.
Chromatic aberration
A lens aberration producing an overall blurred image; the inability of a lens to bring all wavelengths of light (especially red and blue) into the same plane of focus; usually present in regular large-aperture telephoto and super-telephoto lenses; does not improve by stopping down the lens; correctable through the use of Iow Dispersion (ED, LD SD) glass. Basically, this aberration is caused by light rays of different wavelengths coming to focus at different distances from the lense. Blue will focus at the shortest distance and red at the greatest distance. Since the natural rays of light are a mixture of colors, each aberration will give a different value corresponding to each color thus producing blurred images.
CI
Contrast Index (sounds like composite index for stock market, ha!) Numeric rating indicating the optimum development contrast for negative materials.
Clearing Agent
A chemical that neutralises hypo in film or paper, reducing wash time and helping to provide a more stable image.
Click stop.
Ball bearing and recess or similar construction used to enable shutter speeds, aperture values, etc. to be set by touch.
Close-Up
A picture taken with the subject close to the camera-usually less than two or three feet away, but it can be as close as a few inches.
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.
Correction of Aberrations at Close Distance Focusing (or CRC)
In general, lenses are designed for maximum performance at infinity. Accordingly, when the lense barrel is fully extended to the shortest focusing distance, resolution is reduced. Although this is negligible for ordinary lenses, it becomes increasingly important in lense specially designed for close distance photography. Lense designers adopted a system where mechanism moves certain lense components as a unit automatically correcting for aberrations. This assures high lense performance throughout the focusing range.
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 negative.
Film designed to produce colour image with both tones and colours reversed for subsequent printing to a positive image, usually on paper.
Colour reversal.
Film designed to produce a normal colour positive image on the film exposed in the camera for subsequent viewing by transmitted light or projection on to a screen.
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.
CompactFlash
Most digital cameras with PC Card interfaces use a storage technology called CompactFlash. Standard supported by the CompactFlash Association. CompactFlash is ATA compatible and will fit into any Type II or Type III slot when used with a passive adapter.
Component.
Part of a compound lens consisting of one element (single lens) or more than one element cemented or otherwise joined together. A lens may therefore be described as 4-element, 3-component when two of the elements are cemented together.
Composition
The pleasing arrangement of the elements within a scene-the main subject, the foreground and background, and supporting subjects.
Computerised flash.
Electronic flash guns which sense the light reflected from the subject, and cut off their output when they have received sufficient light for correct exposure. Most units must be used on or close to the camera for direct lighting only. And the camera lens must be set to a specific aperture (or a small range of apertures) determined by the speed of the film in use.
Condenser.
Generally a simple lens used to collect light and concentrate it on a particular area, as in enlarger or projector. Frequently in the form of two planoconvex lenses in a metal housing. A condenser, normally of the fresnel type, is used to ensure even illumination of the viewing screens on SLR cameras.
Condenser Enlarger
An enlarger with a sharp, undiffused light that produces high contrast and high definition in a print. Scratches and blemishes in the negative are emphasised.
Contact Print
A print made by exposing photographic paper while it is held tightly against the negative. Images in the print will be the same size as those in the negative.
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.
Contact Printer
A device used for contact-printing that consists of a lighttight box with an internal light source and a printing frame to position the negative against the photographic paper in front of the light.
Continuous Servo AF Focus
Autofocus term used by Nikon, the AF sensor detection continues as long as shutter release button is lightly pressed and the reflex mirror is in the viewing position. Useful when the camera-to-subject distance is likely to change.
Contrast Grade
Numbers (usually 1-5) and names (soft, medium, hard, extra-hard, and ultra hard) of the contrast grades of photographic papers, to enable you to get good prints from negatives of different contrasts. Use a low-numbered or soft contrast paper with a high contrast negative to get a print that most closely resembles the original scene. Use a high-numbered or an extra-hard paper with a low-contrast negative to get a normal contrast paper.
Contrasty
Higher-than-normal contrast including very bright and dark areas. The range of density in a negative or print is higher than it was in the original scene.
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.
Continuous Servo (Nikon's term) :
AF Focus detection continues as long as shutter release button is lightly pressed and the reflex mirror is in the viewing position. Useful when the camera-to subject distance is likely to change.
CPU (Central Processing Unit)
The electronic component that controls an electronic product's functions. Essentially, all automatic cameras have at least a CPU to control various functions of the cameras. Some top models have three to five CPU to handle individual task functions - some handle the exposure, one handle the autofocus and so on. The latest on some top models utilising 8 or 16 bits chips now. Newer autofocus lenses have built-in CPUs to relay information relating to focal length, distance info, lens type to the camera body for exposure to AF processing.
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.
Curvature of Field. This optical defect causes points on an object plane perpendicular to the lens axis to focus on a curved surface rather than a plane.
C 41
Kodak's standard chemical process for developing color negative film, an industrial reference standard.
CRC (Close Range Correction System): Check Nikon's terms page for more.
"Classic" format - one of the three selectable Advanced Photo System print formats; identical to the 2:3 aspect ratio used in 35 mm photography and suitable for most general-purpose shots.
Camera Angles
Various positions of the camera (high, medium, or low; and left, right, or straight on) with respect to the subject, each giving a different viewpoint, perspective or visual effect.
Camera shake.
Movement of camera caused by unsteady hold or support, vibration, etc., leading, particularly at slower shutter speeds, to a blurred image on the film. It is a major cause of un-sharp pictures, especially with long focus lenses.
Candid Pictures
Unposed pictures of people, often taken without the subject's knowledge. These usually appear more natural and relaxed than posed pictures.
Capacitor.
Electrical component once more commonly known as a condenser. Stores electrical energy supplied by a power source and can discharge it more rapidly than the source itself. Used in flash equipment, providing reliable bulb firing even from weak batteries, and supplying the surge needed for electronic flash tubes.
Cartridge
A lighttight, factory-loaded film container that can be placed in and removed from the camera in daylight. Some nature of film, like the infra red film, MUST not even try to load or unload film in any possible light existence, absolutely must be in total pitch dark condition to avoid fogging on film.
Cassette
Light-trapped film container used with 35 mm cameras.
Elliptically shaped film cassette designed especially for the Advanced Photo System that serves as the sealed, leaderless container for all System film whether unexposed, exposed or processed.
Cast.
Abnormal colouring of an image produced by departure from recommended exposure or processing conditions with a transparency film, or when making a colour print. Can also be caused by reflection within the subject as from a hat on to the face.
CCD
Electronic sensor used by all autofocus cameras, capable of detecting subject contrast; also an image-receiving device for video camera.
Cds
Cadmium Sulfide (Cell). A battery powered, current-modulating. light-sensing cell that was quite popular with lots of cameras exposure metering system and external metering devices. May be this extra will help, photo conductive material used in exposure meters as alternative to selenium-based or silicon blue photocells. Its electrical resistance decreases as the light falling on it increases. Cds meters use current from an external power source, such as a battery.
Chromatic aberration
A lens aberration producing an overall blurred image; the inability of a lens to bring all wavelengths of light (especially red and blue) into the same plane of focus; usually present in regular large-aperture telephoto and super-telephoto lenses; does not improve by stopping down the lens; correctable through the use of Iow Dispersion (ED, LD SD) glass. Basically, this aberration is caused by light rays of different wavelengths coming to focus at different distances from the lense. Blue will focus at the shortest distance and red at the greatest distance. Since the natural rays of light are a mixture of colors, each aberration will give a different value corresponding to each color thus producing blurred images.
CI
Contrast Index (sounds like composite index for stock market, ha!) Numeric rating indicating the optimum development contrast for negative materials.
Clearing Agent
A chemical that neutralises hypo in film or paper, reducing wash time and helping to provide a more stable image.
Click stop.
Ball bearing and recess or similar construction used to enable shutter speeds, aperture values, etc. to be set by touch.
Close-Up
A picture taken with the subject close to the camera-usually less than two or three feet away, but it can be as close as a few inches.
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.
Correction of Aberrations at Close Distance Focusing (or CRC)
In general, lenses are designed for maximum performance at infinity. Accordingly, when the lense barrel is fully extended to the shortest focusing distance, resolution is reduced. Although this is negligible for ordinary lenses, it becomes increasingly important in lense specially designed for close distance photography. Lense designers adopted a system where mechanism moves certain lense components as a unit automatically correcting for aberrations. This assures high lense performance throughout the focusing range.
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 negative.
Film designed to produce colour image with both tones and colours reversed for subsequent printing to a positive image, usually on paper.
Colour reversal.
Film designed to produce a normal colour positive image on the film exposed in the camera for subsequent viewing by transmitted light or projection on to a screen.
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.
CompactFlash
Most digital cameras with PC Card interfaces use a storage technology called CompactFlash. Standard supported by the CompactFlash Association. CompactFlash is ATA compatible and will fit into any Type II or Type III slot when used with a passive adapter.
Component.
Part of a compound lens consisting of one element (single lens) or more than one element cemented or otherwise joined together. A lens may therefore be described as 4-element, 3-component when two of the elements are cemented together.
Composition
The pleasing arrangement of the elements within a scene-the main subject, the foreground and background, and supporting subjects.
Computerised flash.
Electronic flash guns which sense the light reflected from the subject, and cut off their output when they have received sufficient light for correct exposure. Most units must be used on or close to the camera for direct lighting only. And the camera lens must be set to a specific aperture (or a small range of apertures) determined by the speed of the film in use.
Condenser.
Generally a simple lens used to collect light and concentrate it on a particular area, as in enlarger or projector. Frequently in the form of two planoconvex lenses in a metal housing. A condenser, normally of the fresnel type, is used to ensure even illumination of the viewing screens on SLR cameras.
Condenser Enlarger
An enlarger with a sharp, undiffused light that produces high contrast and high definition in a print. Scratches and blemishes in the negative are emphasised.
Contact Print
A print made by exposing photographic paper while it is held tightly against the negative. Images in the print will be the same size as those in the negative.
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.
Contact Printer
A device used for contact-printing that consists of a lighttight box with an internal light source and a printing frame to position the negative against the photographic paper in front of the light.
Continuous Servo AF Focus
Autofocus term used by Nikon, the AF sensor detection continues as long as shutter release button is lightly pressed and the reflex mirror is in the viewing position. Useful when the camera-to-subject distance is likely to change.
Contrast Grade
Numbers (usually 1-5) and names (soft, medium, hard, extra-hard, and ultra hard) of the contrast grades of photographic papers, to enable you to get good prints from negatives of different contrasts. Use a low-numbered or soft contrast paper with a high contrast negative to get a print that most closely resembles the original scene. Use a high-numbered or an extra-hard paper with a low-contrast negative to get a normal contrast paper.
Contrasty
Higher-than-normal contrast including very bright and dark areas. The range of density in a negative or print is higher than it was in the original scene.
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.
Continuous Servo (Nikon's term) :
AF Focus detection continues as long as shutter release button is lightly pressed and the reflex mirror is in the viewing position. Useful when the camera-to subject distance is likely to change.
CPU (Central Processing Unit)
The electronic component that controls an electronic product's functions. Essentially, all automatic cameras have at least a CPU to control various functions of the cameras. Some top models have three to five CPU to handle individual task functions - some handle the exposure, one handle the autofocus and so on. The latest on some top models utilising 8 or 16 bits chips now. Newer autofocus lenses have built-in CPUs to relay information relating to focal length, distance info, lens type to the camera body for exposure to AF processing.
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.
Curvature of Field. This optical defect causes points on an object plane perpendicular to the lens axis to focus on a curved surface rather than a plane.
C 41
Kodak's standard chemical process for developing color negative film, an industrial reference standard.
Glossary of Photography Terms (D)
D-type AF Nikkor lenses (Only apply to Nikon):
AF Nikkor lenses that send Distance Information to some of Nikon's top cameras, Used for 3D Color Matrix Metering or 3D Multi Sensor Balanced Fill Flash (with Nikon SB 27/SB 26/SB 25 Speedlight). Some third party lens manufacturers are catching up to supply with compatible functions lenses too.
DC (Defocus Image control)
A new type of lens family introduced by Nikon, designated as DC lens. Mainly for portrait photography. The lens enables to control background and foreground blur precisely, resulting in strikingly attractive portraits.
Darkroom
A light tight area used for processing films and for printing and processing papers; also for loading and unloading film holders and some cameras. For image purist, the cycle of photograph is not complete if the darkroom process is not handled personally.
Data Disk
A circular, rotating disk at the end of Advanced Photo System film cassettes that functions as a circular bar code, communicating the film speed, type and exposure length through a sequence of reflective bars to an optical sensor in the camera.
Dedicated Flash
A fully automatic flash that works only with specific cameras. Dedicated flash units automatically set the proper flash sync speed and lens aperture, and electronic sensors within the camera automatically control exposure by regulating the amount of light from the flash. A simple glance can differentiate by identifying the multiple contacts on the hot shoe (the place where the flash is mounted).
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.
Densitometer
An instrument used for measuring the optical density of an area in a negative or print.
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
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. Relating article in this site: Depth of field.
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.
Developer
A solution used to make visible the image produced by allowing light to fall on the light-sensitive material. The basic constituent is a developing agent which reduces the light-struck silver halide to metallic silver. Colour developers include chemicals which produce coloured dyes coincidentally with reduction of the silver halides.
Developing Tank
A light tight container used for processing film, a darkroom's essential accessory.
Diaphragm
An adjustable device inside the lens which is similar to the iris in the human eye; comprised of six or seven overlapping metal blades; continuously adjustable from "wide open" to "stopped down"; controls the amount of light allowed to pass through the lens and expose the film when a picture is taken; a]so controls the amount of depth of field the photograph will have; in lenses designed for single-lens reflex cameras, there are basically two types of diaphragms: Lens opening. A perforated plate or adjustable opening mounted behind or between the elements of a lens used to control the amount of light that reaches the film. Openings are usually calibrated in f-numbers. The more blades used will have a more natural and rounded spots.
There are two types of diaphragms:
Automatic: The most popular type; controlled by a single aperture ring; during viewing and focusing, the diaphragm remains wide open, allowing the maximum amount of light to go to the viewfinder for a bright and easy-to-focus image; at the instant of exposure, it stops down automatically to a particular aperture and then reopens to full aperture immediately afterward.
Manual Preset: Used in some specific lenses like, PC-Nikkor lenses for Nikon for instance; controlled by two separate rings; the preset ring is first set to the desired aperture, then the aperture ring is rotated to stop down the diaphragm manually for metering or prior to taking pictures.
Diffuse Lighting
Lighting that is low or moderate in contrast, such as on an overcast day.
Diffusing
Softening detail in a print with a diffusion disk or other material that scatters light.
Diffusion-Condenser Enlarger
An enlarger that combines diffuse light with a condenser system, producing more contrast and sharper detail than a diffusion enlarger but less contrast and blemish emphasis than a condenser enlarger.
Diffusion Enlarger
An enlarger that scatters light before it strikes the negative, distributing light evenly on the negative. Detail is not as sharp as with a condenser enlarger; negative blemishes are minimised.
DIN
Deutche Industrie Norm (Film speed rating defined by the Deutscher Normenausschuss (German standards organisation).). Numeric rating used to describe emulsion speed for German Made photosensitive materials. Just as the same as ASA and ISO numbers.
Dispersion
The property of materials which have a refractive index that varies according to the wavelength of light, i.e., bend the rays of some colors more than others; a prism placed in the path of a ray of white light bends the blue and violet rays more than the orange and red, so that it spreads out or "disperses" the colors as a continuous spectrum.
Distortion
Even if the other possible aberrations were totally eliminated, images could result that still have a distorted appearance. For an example, an rectangle may appear as a barrel or pin cushion-shaped object. A lens aberration which does not affect the sharpness of the image, but alters the shape of objects; the inability of a lens to render straight lines perfectly straight; does not improve by stopping down the lens; there are two types of distortion:
Barrel: Straight lines are bowed in at the edges of the picture frame re sembling the sides of a barrel; pres ent in small amounts in some wideangle or wideangle-zoom lenses, bu~ uncorrected in fisheye lenses.
Pincushion: The opposite of barrel distortion; straight lines are bowed in toward the middle to resemble the sides of a pincushion; present in smal amounts in some telephoto and telephoto-zoom lenses.
Dodging
Holding back the image-forming light from a part of the image projected on an enlarger easel during part of the basic exposure time to make that area of the print lighter.
Double Exposure
Two pictures taken on one frame of film, or two images printed on one piece of photographic paper. Some cameras can have double exposure level depressed with multiple exposures one even with a motor drive.
Drop-in-Loading (DIL)
Film cassette loading feature in all Advanced Photo System cameras that virtually eliminates film-loading problems by automatically accepting the leaderless cassette and thrusting the film forward to the first unexposed frame without any user intervention.
DX
Digital Index. Coding on the film cartridges used to transmit information in relation to film speed, the length of film and the exposure latitude to the camera. Most films - except some technical films are DX coded - means you need not to worry about wrong setting of the ISO setting of film speed anymore, reducing chances of mistakes. Common speed ISO 25 to 6400 - depends on camera models.
DX Data Exchange
Electrical coding system employed in 35 mm format film that communicates film speed, type and exposure length to the camera.
AF Nikkor lenses that send Distance Information to some of Nikon's top cameras, Used for 3D Color Matrix Metering or 3D Multi Sensor Balanced Fill Flash (with Nikon SB 27/SB 26/SB 25 Speedlight). Some third party lens manufacturers are catching up to supply with compatible functions lenses too.
DC (Defocus Image control)
A new type of lens family introduced by Nikon, designated as DC lens. Mainly for portrait photography. The lens enables to control background and foreground blur precisely, resulting in strikingly attractive portraits.
Darkroom
A light tight area used for processing films and for printing and processing papers; also for loading and unloading film holders and some cameras. For image purist, the cycle of photograph is not complete if the darkroom process is not handled personally.
Data Disk
A circular, rotating disk at the end of Advanced Photo System film cassettes that functions as a circular bar code, communicating the film speed, type and exposure length through a sequence of reflective bars to an optical sensor in the camera.
Dedicated Flash
A fully automatic flash that works only with specific cameras. Dedicated flash units automatically set the proper flash sync speed and lens aperture, and electronic sensors within the camera automatically control exposure by regulating the amount of light from the flash. A simple glance can differentiate by identifying the multiple contacts on the hot shoe (the place where the flash is mounted).
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.
Densitometer
An instrument used for measuring the optical density of an area in a negative or print.
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
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. Relating article in this site: Depth of field.
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.
Developer
A solution used to make visible the image produced by allowing light to fall on the light-sensitive material. The basic constituent is a developing agent which reduces the light-struck silver halide to metallic silver. Colour developers include chemicals which produce coloured dyes coincidentally with reduction of the silver halides.
Developing Tank
A light tight container used for processing film, a darkroom's essential accessory.
Diaphragm
An adjustable device inside the lens which is similar to the iris in the human eye; comprised of six or seven overlapping metal blades; continuously adjustable from "wide open" to "stopped down"; controls the amount of light allowed to pass through the lens and expose the film when a picture is taken; a]so controls the amount of depth of field the photograph will have; in lenses designed for single-lens reflex cameras, there are basically two types of diaphragms: Lens opening. A perforated plate or adjustable opening mounted behind or between the elements of a lens used to control the amount of light that reaches the film. Openings are usually calibrated in f-numbers. The more blades used will have a more natural and rounded spots.
There are two types of diaphragms:
Automatic: The most popular type; controlled by a single aperture ring; during viewing and focusing, the diaphragm remains wide open, allowing the maximum amount of light to go to the viewfinder for a bright and easy-to-focus image; at the instant of exposure, it stops down automatically to a particular aperture and then reopens to full aperture immediately afterward.
Manual Preset: Used in some specific lenses like, PC-Nikkor lenses for Nikon for instance; controlled by two separate rings; the preset ring is first set to the desired aperture, then the aperture ring is rotated to stop down the diaphragm manually for metering or prior to taking pictures.
Diffuse Lighting
Lighting that is low or moderate in contrast, such as on an overcast day.
Diffusing
Softening detail in a print with a diffusion disk or other material that scatters light.
Diffusion-Condenser Enlarger
An enlarger that combines diffuse light with a condenser system, producing more contrast and sharper detail than a diffusion enlarger but less contrast and blemish emphasis than a condenser enlarger.
Diffusion Enlarger
An enlarger that scatters light before it strikes the negative, distributing light evenly on the negative. Detail is not as sharp as with a condenser enlarger; negative blemishes are minimised.
DIN
Deutche Industrie Norm (Film speed rating defined by the Deutscher Normenausschuss (German standards organisation).). Numeric rating used to describe emulsion speed for German Made photosensitive materials. Just as the same as ASA and ISO numbers.
Dispersion
The property of materials which have a refractive index that varies according to the wavelength of light, i.e., bend the rays of some colors more than others; a prism placed in the path of a ray of white light bends the blue and violet rays more than the orange and red, so that it spreads out or "disperses" the colors as a continuous spectrum.
Distortion
Even if the other possible aberrations were totally eliminated, images could result that still have a distorted appearance. For an example, an rectangle may appear as a barrel or pin cushion-shaped object. A lens aberration which does not affect the sharpness of the image, but alters the shape of objects; the inability of a lens to render straight lines perfectly straight; does not improve by stopping down the lens; there are two types of distortion:
Barrel: Straight lines are bowed in at the edges of the picture frame re sembling the sides of a barrel; pres ent in small amounts in some wideangle or wideangle-zoom lenses, bu~ uncorrected in fisheye lenses.
Pincushion: The opposite of barrel distortion; straight lines are bowed in toward the middle to resemble the sides of a pincushion; present in smal amounts in some telephoto and telephoto-zoom lenses.
Dodging
Holding back the image-forming light from a part of the image projected on an enlarger easel during part of the basic exposure time to make that area of the print lighter.
Double Exposure
Two pictures taken on one frame of film, or two images printed on one piece of photographic paper. Some cameras can have double exposure level depressed with multiple exposures one even with a motor drive.
Drop-in-Loading (DIL)
Film cassette loading feature in all Advanced Photo System cameras that virtually eliminates film-loading problems by automatically accepting the leaderless cassette and thrusting the film forward to the first unexposed frame without any user intervention.
DX
Digital Index. Coding on the film cartridges used to transmit information in relation to film speed, the length of film and the exposure latitude to the camera. Most films - except some technical films are DX coded - means you need not to worry about wrong setting of the ISO setting of film speed anymore, reducing chances of mistakes. Common speed ISO 25 to 6400 - depends on camera models.
DX Data Exchange
Electrical coding system employed in 35 mm format film that communicates film speed, type and exposure length to the camera.
Glossary of Photography Terms (E)
E6
Kodak's standard chemical process for developing Ektachrome or compatible slide films from other films makers apart from Kodak.
Easel
A device to hold photographic paper flat during exposure, usually equipped with an adjustable metal mask for framing.
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.
EIS
Electronic Image Stabiliser. Feature that minimises effect of camera shake. Originally designed for video cameras. Canon has transfer the technology over to its EF lenses, we expect more Canon's EF lenses will adopt this feature.
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.
Element.
Single lens used in association with others to form a compound construction.
Emulsion
Micro-thin layers of gelatin on film in which light-sensitive ingredients are suspended; triggered by light to create a chemical reaction resulting in a photographic image. Basically, suspension of light-sensitive silver salts in gelatin.
Emulsion Side
The side of the film coated with emulsion. In contact printing and enlarging, the emulsion side of the film-dull side-should face the emulsion side of the photo paper-shiny side.
Enhanced Back-Printing
An Advanced Photo System feature available in some system cameras that enables users to encode detailed information at the time of picture-taking, such as the date and time of exposure, camera settings, roll title or other custom information for subsequent printing onto the back of their photographs.
Enlargement
A print that is larger than the negative or slide; also see "blowup".
Enlarger
A device consisting of a light source, a negative holder, and a lens, and means of adjusting these to project an enlarged image from a negative onto a sheet of photographic paper.
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.
Existing Light
Available light. Strictly speaking, existing light covers all natural lighting from moonlight to sunshine. For photographic purposes, existing light is the light that is already on the scene or project and includes room lamps, fluorescent lamps, spotlights, neon signs, candles, daylight through windows, outdoor scenes at twilight or in moonlight, and scenes artificially illuminated after dark.
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.
Exposure bracketing :
Shooting the same subject at a range of different exposures. Some camera provides Auto Exposure Bracketing/Flash Exposure Bracketing.
Exposure compensation :
Exposure compensation for available light is activated by changing the shutter speed and/or lens aperture. This is done by using AE L AF-L (Auto Exposure/Autofocus Lock) button or exposure compensation button, or by Auto Exposure Bracketing . In flash photography with a dedicated TTL Speedliqht exposure compensation can also be performed by varying the amount of flash output. Camera-originated exposure compensation affects both the foreground subject and the background; variations in flash output amount affect only the foreground.
Exposure factor.
A figure by which the exposure indicated for an average subject and/or processing should be multiplied to allow for non-average conditions. Usually applied to filters. Occasionally to lighting. Processing, etc Not normally used with through-the-lens exposure meters.
Exposure Latitude
The range of camera exposures from underexposure to overexposure that will produce acceptable pictures from a specific film.
Exposure Meter
An instrument with a light-sensitive cell that measures the light reflected from or falling on a subject, used as an aid for selecting the exposure setting. The same as a light meter.
Extension bellows.
Device used to provide the additional separation between lens and film required for close-up photography. Consists of extendible bellows and mounting plates at front and rear to fit the lens and camera body respectively.
Extension tubes.
Metal tubes used to obtain the additional separation between lens and film for close-up photography. They are fitted with screw thread or bayonet mounts to suit various lens mounts.
Kodak's standard chemical process for developing Ektachrome or compatible slide films from other films makers apart from Kodak.
Easel
A device to hold photographic paper flat during exposure, usually equipped with an adjustable metal mask for framing.
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.
EIS
Electronic Image Stabiliser. Feature that minimises effect of camera shake. Originally designed for video cameras. Canon has transfer the technology over to its EF lenses, we expect more Canon's EF lenses will adopt this feature.
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.
Element.
Single lens used in association with others to form a compound construction.
Emulsion
Micro-thin layers of gelatin on film in which light-sensitive ingredients are suspended; triggered by light to create a chemical reaction resulting in a photographic image. Basically, suspension of light-sensitive silver salts in gelatin.
Emulsion Side
The side of the film coated with emulsion. In contact printing and enlarging, the emulsion side of the film-dull side-should face the emulsion side of the photo paper-shiny side.
Enhanced Back-Printing
An Advanced Photo System feature available in some system cameras that enables users to encode detailed information at the time of picture-taking, such as the date and time of exposure, camera settings, roll title or other custom information for subsequent printing onto the back of their photographs.
Enlargement
A print that is larger than the negative or slide; also see "blowup".
Enlarger
A device consisting of a light source, a negative holder, and a lens, and means of adjusting these to project an enlarged image from a negative onto a sheet of photographic paper.
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.
Existing Light
Available light. Strictly speaking, existing light covers all natural lighting from moonlight to sunshine. For photographic purposes, existing light is the light that is already on the scene or project and includes room lamps, fluorescent lamps, spotlights, neon signs, candles, daylight through windows, outdoor scenes at twilight or in moonlight, and scenes artificially illuminated after dark.
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.
Exposure bracketing :
Shooting the same subject at a range of different exposures. Some camera provides Auto Exposure Bracketing/Flash Exposure Bracketing.
Exposure compensation :
Exposure compensation for available light is activated by changing the shutter speed and/or lens aperture. This is done by using AE L AF-L (Auto Exposure/Autofocus Lock) button or exposure compensation button, or by Auto Exposure Bracketing . In flash photography with a dedicated TTL Speedliqht exposure compensation can also be performed by varying the amount of flash output. Camera-originated exposure compensation affects both the foreground subject and the background; variations in flash output amount affect only the foreground.
Exposure factor.
A figure by which the exposure indicated for an average subject and/or processing should be multiplied to allow for non-average conditions. Usually applied to filters. Occasionally to lighting. Processing, etc Not normally used with through-the-lens exposure meters.
Exposure Latitude
The range of camera exposures from underexposure to overexposure that will produce acceptable pictures from a specific film.
Exposure Meter
An instrument with a light-sensitive cell that measures the light reflected from or falling on a subject, used as an aid for selecting the exposure setting. The same as a light meter.
Extension bellows.
Device used to provide the additional separation between lens and film required for close-up photography. Consists of extendible bellows and mounting plates at front and rear to fit the lens and camera body respectively.
Extension tubes.
Metal tubes used to obtain the additional separation between lens and film for close-up photography. They are fitted with screw thread or bayonet mounts to suit various lens mounts.
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