Photographers’ gobbledygook can be confusing! This photography dictionary will help you find the real significance behind that jargon.
C41
The number given to a Chemical process for developing colour negative film. (created in 1972 by Kodak but adopted universally by every other manufacturer).
Cable release
Flexible cable for firing a camera shutter. Useful for long exposures where touching the camera release by hand could cause camera-shake blur.
(see Exposure, Shutter & Shutter speed)
Camera Format
The size and aspect ratio of an image produced on film or digitally. Large format, medium format, or 35mm, but determined by the actual dimensions of the focal plane or image sensor. Digital capture technologies are confusing the traditional distinctions, since a small image sensor with many pixels is not necessarily better in quality than a larger sensor with less pixels.
(see Format, Large format,Medium format, Pixel & 35mm)
Camera movements
Mechanical Systems most common on large format cameras (and some Medium Format) which provide the facility for lens and film plane movement from a normal standard position. The movements can create greater or lesser depth of field, and correct or distort image shape.
(see Depth of field, Movements & Standard)
Camera obscura
For hundreds of years the camera obscura was a curiosity, consisting of a darkened room with a small hole in one of its walls; a reduced inverted image of the world outside was projected through the hole onto a whitewashed wall opposite; the phenomenon was noted by the Arabs as early as the eleventh century.
By the end of the sixteenth century Italian academics had fitted a converging lens into the hole which produced a much brighter and sharper picture. Artists began to use a collapsible, portable version to reproduce perspective in their landscapes and portraits.
(see Pinhole camera)
A telephoto lens that uses mirrors within its construction to reduce it's overall length. Also known as a reflex or cat.
(see Mirror lens)
CC filter
Abbreviation for colour compensating filter. CC filters are designed primarily for correcting colour bias in colour photo printing. CC2OY, for example, indicates a yellow filtration of 0.2 density.
(see Colour correction)
CCD
Charge Coupled Device (CCD). The Digital camera's 'film'; a CCD converts light into a digital photograph of pixels. When a picture is taken the CCD is struck by light coming through the camera's lens; each of the millions of tiny pixels that make up the sensor converts this light into electrons.
(see CMOS & Pixel)
CD ROM (Compact Disc)
Read only memory/media: an electro-optical data storage medium with the same physical format as an audio disc and a capacity of approximately 650-700mb of data.
(see: Megabyte)
Centre Weighted
A camera metering system which concentrates the light reading mostly to the central portion of the viewfinder and feathering out to the edges. Although in the hands of an inexperienced photographer a 'Matrix' style meter will achieve more correct results many professionals still prefer to use their cameras in manual mode with the meter set to 'centre weighted'! Now regarded as a 'classic', this metering system is included in all quality 35mm SLR's and DSLR's.
(see Matrix Metering, Finder, 35mm & SLR)
CF Card
Compact Flash, a removable card used in larger Digital Cameras.
(see Compact Flash)
Changing bag
A light tight fabric bag, used for safely removing sensitive photographic materials from film holders or backs in daylight.
Chromatic Aberration
The inability of a lens to focus different colours on the same focal plane. Appearing as a 'colour fringe' around objects, especially at the edges of the photograph.
Chrome
A positive transparency designed to be viewed when lit from behind. Used frequently to describe a 'positive' camera film. Large chromes are used for advertising or promotion purposes, and are sometimes known by the kodak brand name duratrans ‘durable transparency’.
(see E6, Trannie & Transparency)
Chromogenic film
Chromogenic literally means 'colour forming'. In chromogenic films the final image is made of coloured dyes formed during processing rather than Silver Halide. A Black & White chromogenic film can be processed along side colour films in a C41 process.
(see C41 & Silver Halide)
Circle of confusion
Disc of light in the image where a point on the subject is not perfectly brought into focus. The eye cannot distinguish between a very small circle of confusion and a true point.
"Clean & tight"
A phrase often used by photographers when describing a well composed (clean) photo which eliminates all inconsequential items from the photo (tight).
Clearing time
"Twice the clearing time" is a popular darkroom term.
Insufficient time in the fix causes film to appear milky. Photographers use a film clipping in the fixer chemical to accurately time this process, after a second clipping is 'clear' the film is ready for washing.
(see Fix)
Clip test
A test to determine accurate development times using a small part of the exposed film as a sample.
Close-up lens
A lens attachment used in front of the camera lens; pictures then could be taken at a closer distance than normal.
(see Extension tubes & Macro lens)
CMOS
Complementary Metal-Oxide Semiconductor (CMOS). An image sensor used in some digital cameras. Its basic function is the same as the CCD.
(see CCD)
Coating
A transparent lens 'Coating' (single or multi) which reduces 'flare' and improves contrast.
(see Multicoating)
Colour Balance
How a particular colour film reproduces the colours of a scene. All Colour films are formulated to be exposed by light of a certain colour quality (daylight or tungsten). It also describes an adjustment in colour photo processes that ensure a neutral scale of grey tones is reproduced accurately, i.e. a grey subject will have no colour cast or bias.
(see Daylight film & Tungsten film)
Colour cast
Overall bias towards one colour in a photograph.
(see Colour Balance)
Colour correction
Filters which help balance the colour rendition of a scene to match the colour response of the eye.
(see CC filters)
Colour Gamut
The complete set of colours found within an image. Printing an image requires transforming the photo from the original RGB color space to the printer's CMYK colour space. This process converts the colours from the RGB which are out of gamut to approximate values within the CMYK space gamut.
Colour Management System
A system for communicating colour reproduction information about digital images between input, display and output devices.
Improves fidelity of image reproduction when properly configured by all involved in a production workflow.
Colour Profile
Colour space information can improve colour fidelity when embedded into a digital image file and referenced within a 'Colour Management System' reproduction workflow.
Colour sensitivity
The response of a sensitive material to the colours of the spectrum
Colour Space
A three-dimensional representation of a colour profile, useful in digital imaging to understand colour performance between input, display and output devices.
(see: Colour Management System)
Colour temperature
Measured in Kelvin, expressed on a scale (i.e.3400K) this indicates the colour content and quality of a light source light such as a lamp.
(see Tungsten film)
Colour temperature
Measured in Kelvin, expressed on a scale (i.e.3400K) this indicates the colour content and quality of a light source light such as a lamp.
(see Tungsten film)
Coma
A lens defect which results in points of light appearing in the image not as points but as discs with comet-like tails.
Compact camera
A small camera that is both easy to use and also small enough to carry in a jacket pocket or hand bag.
(see: Point and Shoot)
Compact Flash
The removable CF card is a popular Digital Camera photo storage system. Although they are larger than SD, Smart Media, XD Picture Card and Memory Sticks 'Professional' use has made them widely available and in very large sizes, currently up to 512 Gigabytes.
(see Memory Stick, Micro Drives, Secure Digital, Smart Media & XD Picture Card)
Complementary colour
The hue most opposite to a given colour. The complementaries for blue, green and red are yellow, magenta and cyan respectively.
Composite
The act of combining two or more images. Today usually accomplished digitally using 'Photoshop'.
(see Photoshop)
Compound lens
Lens system consisting of two or more elements.
Compression
A digital file is compressed by removing redundant information. Some image file compression methods discard visual information that may degrade image quality.
(see JPEG & Lossy)
Compression Ratio
The amount of data in a digital image divided by the amount of data in a version after compression. Higher ratios indicate more compression which may degrade image quality.
(see JPEG & Lossy)
Concave lens
Simple lens, or lens shape within a compound lens, whose surfaces curve inward. Such a lens causes light rays to diverge.
(see Compound lens)
Condenser
A simple lens system which concentrates light from a source into a beam. Condensers are used in equipment such as slide projectors, spotlights and enlargers.
(see Focusing Spot)
Contact print
A print made from placing the negative in 'contact' with a sheet of photo paper and then exposed to light; the resulting "Contact print" is the same size as the negative and therefore not enlarged.
(see Contact printer & Enlargement)
Contact printer
Apparatus used for making contact prints. Usually just a simple frame with a glass top to hold the negative and paper in tight contact during exposure.
Contrast
A subjective judgment of the difference in brightness and density between shadow and highlight areas in an image. Contrast is affected by lighting, lens flare, film type, degree of development, enlarger type and quality of printing.
Contrast grade paper
Graded by numbers (usually 1-5), the contrast grades of Black & White photographic papers, enable us to obtain good prints from negatives of varying contrasts. Use a low-numbered or soft paper with a high contrast negative to get a print that most closely resembles the original scene. Use a high-numbered or a hard paper with a low-contrast negative to obtain a normal contrast print.
(see Multigrade)
Contrasty
Higher-than-normal contrast including very bright and very dark areas. The range of density in a trannie or print is higher than it was in the original scene.
Converging angles
This occurs when the camera is not held or supported vertically. The vertical lines will seem to run together at the top or the bottom of a photo. Most noticeable with photographs of tall buildings.
(see Movements, Rising front, Keystoning & Shift)
Converter
A supplementary lens that can double the length of a telephoto lens (e.g.: 2x converter). Usually fitted between lens and camera body.
Convex lens
Simple lens, or lens shape within a compound lens, whose surfaces curve outward. Such a lens causes rays of light passing through it to converge.
(see Compound lens)
Copy
Not an original. A print, neg., trannie, artwork or 2D object copied on a copystand
(see Copystand & Dupe).
Copyright
A legal property right in an original work of any physical medium of expression, such as photographs. Copyright is more than the right to copy, the owner of copyright holds the exclusive right to reproduce, publicly display, adapt, distribute and to authorize others to do the same.
Copystand
A device that holds a 2D object square with the camera to obtain quality copies of an original, the stand usually has lights attached.
Correction filter
A filter which alters the colour rendition of a scene to suit the colour response of the eye.
(see Colour correction)
Coupled rangefinder
Focusing system in which a rangefinder and the lens focusing mechanism are linked. As the lens is adjusted, the central area of the viewfinder indicates when the lens is in focus (as found on Leica M series Cameras).
Cove
Infinity cove. Found in most large studios and painted white, a solid background that wraps over the floor & walls to create the illusion of an infinite 'white'.
(see Background paper)
Covering power
The maximum area of usable image quality which a lens will produce. Known as the angle of coverage. (Frequently a required knowledge when using a large format camera with "movements").
(see Movements)
Cropping
Printing or using only part of the image that is in the original negative or trannie, usually for a more pleasing composition. Could also refer to the framing of the scene in the viewfinder.
(see Clean & Tight)
Cross process
To develop a film in the wrong process (e.g.: neg.(C41) film in trannie(E6) chemicals) to obtain a sometimes bizarre colour or contrast effect.
(see C41 & E6)
Curvature of field
Lens aberration causing the plane of sharp focus to be curved.
(see Aberration)
Cut film
Large format film available in flat sheets. The most common are in "Imperial sizes": 4 ins x 5 ins and 8 ins x 10 ins .
(see Large format)
Cyclo wall
A cyclo wall, also referred to in various combinations as: infinity, seamless, cyc, cyclo, wall, drop, backdrop and background. A curved wall used as a background of a stage set to suggest unlimited space.
(see Cove)
Cyclorama
A large curtain or wall, often concave, positioned at the back of a Theatrical stage. As the name implies, it often encircles or partially encloses the stage to form a background.
(see Cyclo wall)
CMYK
A colour system based on the four colours used in colour printing: Cyan, Magenta, Yellow and BlacK. Can also be a colour mode used to define colours in a digital image. All Digital cameras & scanners are RGB devices, a colour method based on combinations of the primary colours Red, Green & Blue this is the same as your TV and PC monitor. CMYK is primarily used when preparing digital images that will be printed using the process colours by a printer or publisher on a four colour printing press.
(see RGB)
Glossary provided by www.peterashbyhayter.co.uk, and edited from many varied sources.
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