NSL Photography's™ Glossary of Photographic Terms - C

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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. It is a major cause of photographs which are unsharp, especially with telephoto and macro lenses. Camera shake can be reduced by some holding techniques, monopod and tripod use, as well as the use VR (vibration reduction) or IS (image stabilzation) lenses and camera when available.

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

An electrical component, in the past, known commonly as a condenser. It stores electrical energy supplied by a power source and can discharge it more rapidly than the source itself. It's commonly used in electronic flash units to provide for reliable firing even as batteries loose their charge to supply the power surge needed for electronic flash tubes.

A lighttight, factory-loaded film container which can be placed in and removed from the camera in daylight.

Light-trapped film container used with 35 mm cameras. Elliptically shaped film cassettes have been designed for the Advanced Photo System (APS) which serves as the sealed, leaderless container for all APS film whether unexposed, exposed or processed.

Abnormal coloring of an image produced by a departure from recommended exposure or processing conditions with a transparency film, or when making a color print. Can also be caused by reflection within the subject as from a hat on to the face. A color cast can also be on a digitally produced image.

CCD (Charged Couple Device)
An electronic light sensor used by autofocus cameras, capable of detecting subject contrast. It can also be an image-receiving device for video camera.

Chimping is a term used in digital photography (especially when using a digital single-lens reflex camera) to describe the habit of checking every photo on the camera's LCD display immediately after capture.

Some photographers use the term in a derogatory sense to describe the actions of amateur photographers, but the act of reviewing images on-camera is not necessarily frowned upon by professional or experienced photographers.

The term "chimping" is attributed to Robert Deutsch, a USA Today staff photographer, in September of 1999 when writing a story for the SportsShooter email newsletter.

Chromatic Aberration
A lens aberration producing an overall blurred image due to the inability of a lens to bring all wavelengths of light (especially red and blue) into the same plane of focus. This aberration is more prevalent in large-aperture telephoto and super-telephoto lenses, and does not generally improve by stopping down the lens. Correction can be obtained through the use of Low Dispersion (ED, LD SD) glass. Essentially, 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 colors, each aberration will give a different value corresponding to each color thus producing blurred images.

CI (Contrast Index)
An index or numeric rating indicating the optimum development contrast for negative materials.

Circle of Fear
Animals in the wild have a natural "circle of fear." It's an area surrounding an animal, in which, as the animal is approached, it will normally watch whoever or whatever is getting closer, gradually becoming more afraid. Eventually, at some point with the "circle of fear" penetrated, the animal will either run or fly off, or attack. The size of the "circle" is variable and depends on the attitude of the animal at that moment, whether or not it's aggressive by nature, timid, hungry or injured, etc.

Clearing Agent
A chemical which neutralizes hypo (a chemical fixative used in the process of developing of film or paper), thereby reducing wash time of the same, and helping to provide a more stable image.

Click Stop
A ball bearing and recess or similar construction used to enable shutter speeds, aperture values, etc. to be set by touch.

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. It's also know as a macro photograph.

Close-Up Lens
A lens to permit taking pictures at a closer distance than normal camera lenses allow. It is also known as a macro lens. There are also close-up lens attachments which screw on to the front of a lens, which enable the lens to act like a close-up or macro lens and focus on the subject much closer than normal.

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. In digital photography color balance is know as white balance, and digital cameras general have both automatic and manually controlled white balance. Automatic white balance cannot accurately correct color balance in all light situations.

Color Space
It is the range of colors that can be reproduced on a computer monitor or in print form. The most commonly used color spaces for digital imaging are the baseline sRGB and wider-gamut Adobe RGB (1998). Both sRGB and Adobe RGB are based on the mathematical RGB (red, green, blue) color model which is well known to define the colors shown on a computer monitor.

Color Temperature
Description of the color of a light-source by comparing it with the color of light emitted by a (theoretical) perfect radiator at a particular temperature expressed in degrees kelvin (K). Thus "photographic daylight" has a color temperature of about 5500K. On a digital camera the white balance setting controls how the camera deals with the color temperature of the light entering the camera.

A lens aberration restricted to off axis image points. It has to do with 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 wide-angle lenses with large maximum apertures, but it will improve by stopping down the lens.

Many digital cameras with PC Card interfaces use a storage technology called CompactFlash. It is a standard supported by the CompactFlash Association.

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

The range of difference in the light to dark areas of a negative, print, slide or digital image (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. It could also be described as the 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
Autofocus, is a term first 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.

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.

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.

Correction of Aberrations at Close Distance Focusing (or CRC)
Lenses are generally 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 lenses specially designed for close distance photography (close-up or macro lenses). Lens designers adopted a system where a mechanism moves certain lens components as a unit automatically correcting for aberrations. This assures high lens performance throughout the focusing range.

Crop Factor
Many digital single lens reflex (DSLR) cameras have a different sensor size compared to that of a standard 35mm or full frame DSLR camera. The crop factor is the ratio of the sensor size of a camera to a 35mm or full-frame sensor based camera. For example, a DX or APS-C camera with a smaller sensor size compared to an FX or full-frame sensor camera has a crop factor of 1.5.

Cropping is the removal of the outer parts of an image to improve framing, accentuate subject matter or change the aspect ratio of the image. Depending on the application, cropping can be performed on a physical photograph, or achieved digitally using image editing software.

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