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***Steve*** · 23-01-2005, 11:00

C

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:
Un-posed 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.

Cast:
Abnormal colouring of an image produced by incorrect white balance or colour temperature settings are used. Can also be found on prints due to many different types of ink and paper combinations. Se colour profiling for more information. Can also be caused by reflection within the subject as from a hat on to the face etc.

CCD:
Electronic sensor used by autofocus cameras, capable of detecting subject contrast.

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 lens. Blue will focus at the shortest distance and red at the greatest distance. Since the natural rays of light are a mixture of colours, each aberration will give a different value corresponding to each colour thus producing blurred images. Often visible as coloured “halos” in digital pictures.

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 mm.

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 lens barrel is fully extended to the shortest focusing distance, resolution is reduced. Although this is negligible for ordinary lenses, it becomes increasingly important in lens specially designed for close distance photography. Lens designers adopted a system where mechanism moves certain lens components as a unit automatically correcting for aberrations. This assures high lens 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.

Colour Balance:
How a camera reproduces the colours of a scene. Colour films are made to be exposed by light of a certain colour quality such as daylight or tungsten. Digital cameras do this by setting the white balance or colour temperature. Colour balance also refers to the reproduction of colours in colour prints, which can be altered during the printing process and are directly affected by colour profiling.

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. Available in many sizes and speeds.

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 camera shutter.

Contrast:
The range of difference in the light to dark areas of a image (also called density); the brightness range of a subject or the scene lighting. It may be also explained as tonal difference. A image 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.

Continuous Servo AF Focus or AI Servo:
Autofocus term used, 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. The camera “tracks” the subject keeping it in focus.

Contrasty:
Higher-than-normal contrast including very bright and dark areas. The range of density in a image 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 centre of the image; this aberration is very difficult to eliminate in wide-angle lenses with large maximum apertures; it can be reduced by stopping down the lens.

Continuous Servo:
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. 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, usually for a more pleasing composition, in medium 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.

23-01-2005, 11:00	#3 (permalink)
*Steve* Pixalo Crew Join Date: Jan 2005 Location: An Englishman living in Germany Posts: 16,361	C C 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: Un-posed 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. Cast: Abnormal colouring of an image produced by incorrect white balance or colour temperature settings are used. Can also be found on prints due to many different types of ink and paper combinations. Se colour profiling for more information. Can also be caused by reflection within the subject as from a hat on to the face etc. CCD: Electronic sensor used by autofocus cameras, capable of detecting subject contrast. 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 lens. Blue will focus at the shortest distance and red at the greatest distance. Since the natural rays of light are a mixture of colours, each aberration will give a different value corresponding to each colour thus producing blurred images. Often visible as coloured “halos” in digital pictures. 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 mm. 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 lens barrel is fully extended to the shortest focusing distance, resolution is reduced. Although this is negligible for ordinary lenses, it becomes increasingly important in lens specially designed for close distance photography. Lens designers adopted a system where mechanism moves certain lens components as a unit automatically correcting for aberrations. This assures high lens 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. Colour Balance: How a camera reproduces the colours of a scene. Colour films are made to be exposed by light of a certain colour quality such as daylight or tungsten. Digital cameras do this by setting the white balance or colour temperature. Colour balance also refers to the reproduction of colours in colour prints, which can be altered during the printing process and are directly affected by colour profiling. 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. Available in many sizes and speeds. 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 camera shutter. Contrast: The range of difference in the light to dark areas of a image (also called density); the brightness range of a subject or the scene lighting. It may be also explained as tonal difference. A image 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. Continuous Servo AF Focus or AI Servo: Autofocus term used, 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. The camera “tracks” the subject keeping it in focus. Contrasty: Higher-than-normal contrast including very bright and dark areas. The range of density in a image 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 centre of the image; this aberration is very difficult to eliminate in wide-angle lenses with large maximum apertures; it can be reduced by stopping down the lens. Continuous Servo: 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. 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, usually for a more pleasing composition, in medium 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.