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All Things Photography - Photography terms Category: Arts > Photography Date & country: 28/08/2013, USA Words: 193

Digital Film
Quite simply that. Solid state flash memory cards in place of emulsion film.

Digitisation
The process of converting analogue information into digital for use by a computer.

Depth of Field
(DOF). The range of items in focus in an image. This is controlled by the focal length and aperture opening of a lens. A large or wide aperture gives a shallow depth of field (not much range in focus) and a smaller or narrow aperture give a large depth of field (more range in focus).

DC
Direct Current. Battery power such as 9v DC battery

Decompression
Process by which the full data content of a compressed file is restored.

Contrast
The measure of rate of change of brightness in an image.

Continuous Autofocus
As it says. The auto focus system is continuously working on focussing on the subject.

Compression
A Digital photograph creates an image file that is enormous. To enable image files to become smaller and more manageable cameras employ some form of compression such as JPEG. RAW and TIFF files have no compression and take up more space.

Compact Flash
See CF. This is the most commonly used type of memory. It is small, removable and available in a wide range of sizes up to 12GB.

Colour Space
Digital cameras use known colour profiles to generate their images. The most common is sRGB or Adobe RGB. This along with all of the other camera data is stored in the Exif header of the Jpeg file. The colour space information ensures that graphic programs and printers have a reference to the colour profile that the camera used at the time of tak...

Colour Correction
To correct or enhance the colours within an image.

Colour Depth
Digital Images can approximate colour realism but the process is referred to as colour depth, bit depth or pixel depth. Most modern computer displays use 24 bit true colour. It displays the same number of colours that the human eye can discern, about 16 million.

Colour Cast
This is a very unwanted tint of one colour in an image caused by the wrong amount of Cyan, Magenta and Yellow. It can be corrected using your editing software.

Codec
A Codec compresses information to enable it to be sent across a network much faster. It will also decompress information received via the network.

Colour Balance
The accuracy with which the colours captured in the image, match the original scene.

CMS
Colour management system. A software program designed to ensure colour matching and calibration between video and/or computer monitors and any form of hard copy output.

CMYK
Cyan, Magenta, Yellow and BlacK. Colours used by most printers to produce your prints. Colour shifts can be caused when the colour management system tries to convert your PC's RGB files to CMYK. Before printing, try converting your images to CMYK and see what the difference is.

CIFF
Camera Image File Format. This is an agreed type of image storage used by many camera makers.

CMOS
Complementary Metal Oxide Semiconductor (now you can see why it is abbreviated) - Another imaging system used by digital cameras. These produce lower amounts of power consumption, but are not as popular as the CCD sensors used in most digital SLR's

Banding
An artefact of colour gradation in computer imaging. When graduated colours break into larger blocks of a single colour, the smooth look of a proper gradation is reduced.

Backlight
The illumination for a colour LCD display on digital cameras or phones.

Back Lit
Meaning the subject is lit from behind which can cause underexposing. Is also used for portrait photography for special effects and bringing catchlights to the hair.

AVI
Movie clip in Windows AVI format. A lot of digicams now have this feature for producing small video clips.

Automatic Focus
The lens on the camera focuses automatically when the shutter is half pressed. The viewfinder normally has focussing points shown to assist the user in knowing what will be in focus.

Automatic Exposure
The camera sets the shutter speed and aperture for the correct exposure according to the light.

Aspherical Lens
A lens with edges flattened so that it is not a perfect sphere. These produce a much superior image.

Archive
A collection of data in long term storage, usually the hard drive on your PC or an external hard drive.

Aspect Ratio
The ration of horizontal to vertical dimensions of an image. For example, 35mm slide film = 3:2, TV = 4:3, HDTV = 16:9, 4x5 Film = 5:4.

Aperture Priority AE
When using this mode, the user selects the aperture giving control over the Depth of Field. A large aperture letting more light in gives a small depth of field, meaning not much will be in focus. Whereas a small aperture, not letting much light in, will give a greater depth of field or more will be in focus from the front to back of the image.

Aperture
The lens opening that allows more, or less light onto the sensor formed by a diaphragm inside the actual lens.

Angle of View
This is calculated by the focal length of the lens and the size of the image sensor. The 35mm equivalents differ according to the sensor size.

and
audio. Typically a VCD can hold about 74 minutes (650MB) of video and stereo quality audio. The video and audio are stored in MPEG-1 format and follow certain standards (White Book). VCD video quality is roughly the same as VHS video.

Aliasing
This is an effect caused by sampling an image at to low a rate. It causes rapid change (high texture) areas of an image to appear as a slow change in the sample image. Once this has happened, it is extremely difficult to reproduce the original image from the sample.

AE Lock
This enables you to lock the current exposure reading and re-frame the shot using the same setting. A half-press of the shutter is normally required to activate this function, fully pressing only when you want to capture the image.

Add-on Lens
Some point and shoot digicams have a filter thread on The front of The fixed lens that will enable The attachment of an additional lens. Usually wide-angle or telephoto.

actual
value is 1,073,741,824 bytes (1024 megabytes).

AC Power
Alternating Current which is used to operate your Digital camera directly from The mains supply rather than a battery. Sometimes supplied, but normally requires additional expense.

AA
Power source/battery type. Also NiCad and NiMH

Chromatic Aberration
Also known as purple fringing. It is fairly common in 2MP digital cameras and above, especially if they have long telephoto lenses. You can see it when a dark area is surrounded by a highlight. In between the dark and light, you may see a band of purple pixels that shouldn't be there. There are ways of removing this which I have covered in the Ph...

Channel
One piece of information stored with an image. For example, a true colour image has 3 channels, red, green and blue.

Chroma
The colour of an image element or pixel. A chroma is made up of saturation plus the hue values, but is separate from the luminance value.

CF
Compact Flash card. Used in your digital camera to record images. Storage space ranges from 16MB up to 12GB. A company in Japan is currently developing a CF card that will store 2TB of information or 2,048 Gigabytes.

Centre -Weighted
Term used to describe an automatic exposure system that uses just the centre portion of the image to adjust the overall value. So in effect, the exposure will be weighted to what you see towards the centre of your viewfinder.

CD
Compact Disc. You should have heard of these by now. Storage media capable of holding around 650MB of data. These come in 2 forms;

Card Reader
Used for transferring data from your flash memory card to your PC. A better way of transferring your image files than connecting the camera to your PC. Sometimes the cameras circuitry can become corrupt. Better to fry a memory card than your camera.

cannot
interchange flash units and cameras. I.e. a Nikon speedlight on a Canon camera.

Calibration
The act of adjusting the colour of one device to match that of another. For example when you match the calibration of your screen to that of your printer to ensure what you see is what you print. It is also used in the film SLR's Canon EOS-3 and EOS 5 which have eye-controlled focussing. You calibrate the cameras focussing to where your eye is lo...

Bulb
Term used for a long exposure setting normally more than 30 seconds. The start of the exposure is made by pressing the shutter, only ending when the shutter button is released. Excellent for night photography and a remote release is recommended to prevent camera shake as you press the shutter button.

Buffer
Temporary storage areas held in your camera or computers RAM. This acts as a temporary holding area for data that will be manipulated by the CPU before saving it to another device. For example if you are shooting in continuous mode, when the RAM buffer on your digital camera is full it will slow to a much slower rate while the buffer empties to y...

Borderless
Quite simply, this means a printed photograph with no border around it.

Brightness
Value of a pixel in a digital image giving its value of lightness from black to white, with o being black and 255 being white.

BMP
Bitmapped graphics file format which is popular with Windows PC's. It is an uncompressed file format like a TIFF.

Blooming
An effect caused by overexposing a CCD or sensor to too much light. This can cause distortions of the subject and/or colour.

Bitmap
The method of storing information that actually maps an image pixel bit by bit. Formats include; .bmp, .pcx, .pict, .tif, .tiff, .gif. Most picture files are bit-mapped.

Bit Depth
Refers to the colour or grey scale of each individual pixel. For example a pixel with 8 bits per colour (red, green and blue), gives a 24 bit image. 24 bit resolution is 16.7 million colours.

Barrel Distortion
A common geometric lens distortion causing an aquired image to pucker towards the centre and be rounded along the outer edges.

Bit
The smallest unit of memory. The word comes from binary and digit or 1 and 0. Also sometimes known as on and offs.

Focus Lock
Focus lock means pre-focussing the subject and re-framing by moving the camera. This is done by half pressing the shutter to focus and fully pressing to expose. Done to ensure crisp, sharp eyes for example.

Frame
One of many still pictures that make up a video.

Frame Rate
Number of frames that are shown or sent each second. Live action is around 30 frames per second.

Gamma
Measure of the amount of contrast in an image according to the properties of a gradation curve. High contrast = High Gamma and Low = Low.

Focal Length
A lens' angle of view. Such as Wide angle, standard or telephoto.

Flat Bed Scanner
Optical Scanner in which the original image remains stationary while the CCD sensors pass over or under it. The scanned image is held flat by the lid hence the name.

Fixed Focal Length
Basically a non zoom lens. 100mm, 50mm, 200mm etc.

Flash Memory
This is the equivalent to film for digital cameras. It can be re-used over and over and some of the better brands have a lifetime warranty. Types include Compact Flash (CF), Smartmedia, memory stick etc.

Firmware
A micro program often used and stored in ROM. Normally the ROM based software is in all computer based products from PC's to digital cameras. You will often see firmware updates for electronic goods that deal with problem issues.

File Format
Type of program or data file. Includes JPEG, TIFF and BMP

Fill in Flash
See Fill in Flash

FireWire
, it is a high-speed input or output bus used by digital video devices, film or flatbed scanners, and high end digital still cameras & PC's.

FireWire
Officially known as the IEEE 1394 protocol. A high speed data transfer interface used on digital camcorders and the more expensive Digital SLR's.

EXIF
Exchangeable Image File Format. The embedded information about camera and exposure for each image. Most decent graphics programs can read this information.

Exposure
Amount of light that hits the image sensor of film controlled by the shutter speed and aperture.

Exposure Bracketing
Camera will take 3 or 5 images and varies the exposure up or down for each photograph ensuring at least one will be well exposed.

File
A collection of information like data, text or images which are saved on a CD. DVD or hard drive.

DVD
Digital Versatile Disk. DVD is DVD recorded on a DVD-R or DVD-RW disc.

Dye Sub
Dye sublimination is a printing process where the colour dyes are thermally transferred to the printing media. The printers use CMYK colour format. The paper is run in and out of the printer 4 times, once for each colour (C, M and Y) and a fourth time when a protective overcoat is applied. Dye sub is continuous tone printing, it prints tiny squar...

EV
Exposure Value. The ability to override the auto exposure system to under or over expose the image.

DRAM
Dynamic Random Access Memory. A type of volatile memory, which is lost when the power is turned off.

DRAM Buffer
All digicams have a certain amount of fixed memory to facilitate image processing before the finished picture is saved to the flash memory card. Cameras with burst more have a larger buffer of 32MB or bigger to cope with the files however, they are more expensive.

DSLR
Digital Single Lens Reflex (SLR). Camera with interchangeable lens.

DPI
Dots per Inch. This is a measurement value used to describe the resolution of a display screen or that of a printer

DPOF
Digital Print Order Format. This allows you to embed printing information on your memory card. You just select the photographs that you want printed and how many prints to be made. Some photo printers such as Pictbridge use this information at print time.

DOF
Abbreviation of Depth of Field.

Download
Term used for the transference of image data from the camera to your computer. Can be done via a serial port or the faster USB port. Downloads can also be done via Bluetooth or Infra-red without the need for cables.

Dioptre Adjustment
This adjusts the optical viewfinder's magnification factor to suit the eyesight of the cameras user. There should be a knob or dial near the viewfinders eyepiece, however, not all cameras have this feature.

Gamma Correction
With reference to displaying an image accurately on a computer screen, Gamma correction controls the overall brightness of an image. Images which are not properly corrected can look either too dark or bleached out.

Gamut
This is the range of colours that are available in an image or output process. Gamut is generally used in describing the capabilities of a printer to reproduce colours accurately and vibrantly.

GIF
A graphic file format mainly used for Web graphic or small animated (GIF) files. Not good for photographs as it only contains a maximum of 256 colours.

Gigabyte
(GB)

Gradation
A smooth transition between black and white, one colour and another or colour and no colour.

Grey Level
This is the brightness level of a pixel representing it's lightness from black to white. It is usually defined as a value from 0 to 255, with 0 being black and 255 being white.

Grey Scale
A term used to describe an image containing shades of grey rather than colour. Most commonly referred to as a black and white photograph.

Halftone Image
An image reproduced through a special screen made up of dots of various sizes, to simulate shades of grey in an image. Normally used for magazine or newspaper reproduction of images. It is also how modern inkjet printers work. Half toning or dithering are the methods used to produce a smooth gradation of colour versus distinct bands of colour or ...

HD
Hard drive (HDD). This is the internal, large-capacity storage unit in home computers, normally the C-Drive

HDTV
High Definition Television. New video standard that will give 1,125 lines in the United States instead of the traditional 525 NTSC standard lines. The aspect ratio is 16:9 versus 4:3 of normal TV's.

Histogram
A histogram is a bar graph analysis tool that is used to identify contrast and dynamic range of any image. Histograms are found in the more advanced digi-cams and software programs (graphic editors), such as Adobe Photoshop 7, CS or Elements, and are used to manipulate images. The histogram shows a scale of 0 - 255 (left to right) with 0 being bl...

ICC Profile
The International Colour Consortium is a group that sets the standard guidelines for colour management in the imaging world. Most monitors, printers and scanners (as well as digital cameras), usually come with a driver disc for Windows and Mac systems that includes ICC profiles for that particular device. Colour profiles simply let one piece of...

IEEE-1284
High-speed, bidirectional parallel port specification used on Windows PC's, used mostly for printers.

iESP
Olympus' exposure metering system.

iLink
Sony's term for the IEE-1394 FireWire data port found on Sony camcorders.