Glossary / Terms for Digital Cameras

MrGuvernment

MrGuvernment

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WORK IN PROGRESS​

Last update 11.28.05​


please give me at least 1 day before posting additions, i am currently going through many sites to get as many terms as i can.​

This is a start to a post for Digital Camera terms / glossary obtained from various sources

If you wish to see something that is missing, please keep it in the below format

Term - explination

- also include any links as to where you got the information from. As we find better / more in depth explained terms they will replace ones here.


  • Advanced Camera – Advanced digital cameras offer owners the option of manually controlling a variety of camera settings, including focus, aperture, and shutter speed.
  • Ambient light – The natural light in a scene.
  • Archival – The ability of a material, including some printing papers and compact discs, to last for many years.
  • Aperture – A small, circular opening inside the lens that can change in diameter to control the amount of light reaching the camera's sensor as a picture is taken. The aperture diameter is expressed in f-stops; the lower the number, the larger the aperture. For instance, the aperture opening when set to f/2.8 is larger than at f/8. The aperture and shutter speed together control the total amount of light reaching the sensor. A larger aperture passes more light through to the sensor. Many cameras have an aperture priority mode that allows you to adjust the aperture to your own liking. See also shutter speed.
  • Application – A computer program, such as an image editor or image browser.
  • Buffer – Memory in the camera that stores digital photos before they are written to the memory card.
  • Burning – Selectively darkening part of a photo with an image editing program.
  • CCD – Charge Coupled Device: one of the two main types of image sensors used in digital cameras. When a picture is taken, the CCD is struck by light coming through the camera's lens. Each of the thousands or millions of tiny pixels that make up the CCD convert this light into electrons. The number of electrons, usually described as the pixel's accumulated charge, is measured, then converted to a digital value. This last step occurs outside the CCD, in a camera component called an analog-to-digital converter.
  • CCITT Group III – Data compressed in one dimension yielding an average data reduction of about 5:1 or 6:1. The most common implementation of CCITT Group III is the data reduction circuit found in FAX machines. This technique is also known as "run length encoded."
  • CCITT Group IV – Compression in two dimensions yielding an average data reduction of 25:1 or better. CCITT Group IV compression requires the execution of 80-million bit oriented operations. The resulting compressed file is roughly the same size as a vector file consisting of graphics.
  • CMOS – Complementary Metal-Oxide Semiconductor: one of the two main types of image sensors used in digital cameras. Its basic function is the same as that of a CCD. CMOS sensors are currently found in only a handful of digital cameras.
  • CMYK – Cyan, Magenta, Yellow, Black. The four colors in the inksets of many photo-quality printers. Some printers use six ink colors to achieve smoother, more photographic prints. The two additional colors are often lighter shades of cyan and magenta.
  • CompactFlash™ – A common type of digital camera memory card, about the size of a matchbook. There are two types of cards, Type I and Type II. They vary only in their thickness, with Type I being slightly thinner. A CompactFlash memory card can contain either flash memory or a miniature hard drive. The flash memory type is more prevalent.
  • Compression – Process of compacting digital data, images and text. Software algorithms search the raster image to build a greatly condensed (from a file storage perspective) format of the image. In the case of CCITT Group IV, the file size reduction is about 25:1. The actual compression factor is greatly dependent upon the quality of the scan and upon the density of the information.
  • Contrast – The difference between the darkest and lightest areas in a photo. The greater the difference, the higher the contrast.
  • Decompression – Process of returning a compressed file to its full bitmap.
  • Digital camera – A camera that captures the photo not on film, but in an electronic imaging sensor that takes the place of film.
  • Digital Zoom - Most digital cameras provide two methods for zooming: optical and digital. Unlike optical zoom, which uses the optics of the lens to magnify the size of an image, digital zoom discards pixels around the edge of an image, fitting the remaining pixels into the same space to give the appearance of zoom. Since digital zoom comes at the expense of resolution, you should always choose a camera based on its optical zoom, not the digital or combined figure.
  • Dodging – Selectively lightening part of a photo with an image editing program.
  • DPI – Dots per inch: A measurement of the resolution of a digital photo or digital device, including digital cameras and printers. The higher the number, the greater the resolution.
  • EPS – Encapsulated Postscript, a computer file standard set by Adobe for printers, which is the mathematical definition of shapes, lines, color and space. This is one of the most accurate ways to define a font or image, but creates much larger file size. EPS files also add page description information to the files. Used on all computer, but not all postscript files are the same, nor readable between programs. EPSF is an IBM file generally, EPSP is usually found on Macintosh, and there are many different variations of each type.
  • EXIF – Exchangeable Image File: the file format used by most digital cameras. For example, when a typical camera is set to record a JPEG, it's actually recording an EXIF file that uses JPEG compression to compress the photo data within the file.
  • External flash – A supplementary flash unit that connects to the camera with a cable, or is triggered by the light from the camera's internal flash. Many fun and creative effects can be created with external flash.
  • Extended Zoom - Extended zoom digital cameras offer 8x optical zoom or greater, providing far more telephoto power than most other digital cameras (the average digital camera offers 3- or 4x optical zoom). On most digital cameras, a 10x optical zoom is approximately the equivalent of a 380mm lens.
  • File Format – The specific organization of data within a file. There are multiple raster and vector file formats, including TIFF, IOCA, Tiled TIFF, IGES and DXF. Some file formats have been specified for file interchange to facilitate data storage.
  • Fill flash – A flash technique used to brighten deep shadow areas, typically outdoors on sunny days. Some digital cameras include a fill flash mode that forces the flash to fire, even in bright light.
  • Filter – A specialized mini-application to extend or offer unique expansions of a software package. Usually through the use of plug-in architecture. This is a key component of many imaging software packages
  • Fire – Slang for shooting a picture. Example: I pressed the shutter button to fire.
  • Firmware – An Often-used microprogram or instruction set stored in ROM. Usually refers to the ROM-based software that controls an unit. Firmware is found in all computer based products from Cameras to Digital Peripherals
  • GIF – Graphic Interface designed by CompuServe for using images on line. This is a 256 color or 8 bit image.
  • GIF 89 – The most recent GIF standard that allow the selection of area for transparency, primary use is on the internet and other on-line services. Like GIF it is 256 color or 8 bit imaging
  • GUI – Pronounced Gooey, stands for graphic user interface. Refers to the computer interface with software in a user friendly appearance.
  • Grayscale – A photo made up of varying tones of black and white. Grayscale is synonymous with black and white.
  • Highlights – The brightest parts of a photo.
  • Histogram – A graphic representation of the range of tones from dark to light in a photo. Some digital cameras include a histogram feature that enables a precise check on the exposure of the photo.
  • Image – Electronic representation of a document, stored and displayed as a bitmap. Various compression techniquest are in use to minimize file size and network load.
  • Imaging – Term commonly used to describe both the products and industry dealing with images.
  • Image Noise - Image noise creates specks of the wrong color in a digital image. Image noise usually occurs in low-light conditions when a camera's light sensor registers an incorrect value, for instance recording yellow when it should record black. This error causes small dots to appear in the image. Higher quality cameras should have very little noise, even at high ISO settings.
  • Image resolution - The number of pixels in a digital photo is commonly referred to as its image resolution.
  • Index Color - Reduced Color mapping, 8 bit or less. Done to reduce images to their smallest size.
  • ISO speed – A rating of a film's sensitivity to light. Though digital cameras don't use film, they have adopted the same rating system for describing the sensitivity of the camera's imaging sensor. Digital cameras often include a control for adjusting the ISO speed; some will adjust it automatically depending on the lighting conditions, adjusting it upwards as the available light dims. Generally, as ISO speed climbs, image quality drops.
  • Jaggies – Slang term for the stair-stepped appearance of a curved or angled line in digital imaging. The smaller the pixels, and the greater their number the less apparent the "jaggies". Also known as pixelization.
  • JPEG – An acronym for Joint Photographic Experts Group, a JPEG is the most commonly used type of digital image format. By eliminating very subtle color distinctions that the human eye usually cannot detect, JPEG images are compressed so that they can save faster and use less space. Because JPEG format actually alters an image, it's compression is said to be "lossy," meaning that a certain amount of data is lost every time a JPEG is edited, saved, and compressed again.
  • Kilobyte – 1024 bytes, written KB. used to refer to size of files, relates to amount of information in a file.
  • Lab Color – L*a*b* is a color model developed by the Centre Internationale d´Eclairage (CIE). These standards are internationally accepted standards for all colormetric measurements. The Lab model, like other CIE color models, defines color values mathematically, in a device independent manner. Lab color is consistent color regardless of the device producing the color.
  • LCD – Liquid Crystal Display: a low-power monitor often used on the top and/or rear of a digital camera to display settings or the photo itself.
  • LPI – Printing term for Lines per Inch.
  • Macro Mode - Macro mode allows a digital camera to take close-up pictures of small objects like flowers, insects, coins, etc. Macro capabilities vary by camera- check a camera's reviews to see how its macro mode performs.
  • Media – Material that information is written to and stored on. Digital photography storage media includes CompactFlash cards and CDs.
  • Megabyte - A megabyte (MB) is a unit of data used to describe the size of digital images and the capacity of a digital memory card. Memory cards are available in sizes ranging from 8MB to 2 Gigabytes (a Gigabyte is the equivalent of 1,024MB).
  • Megapixe – A measure of resolution that reflects the ability of a digital camera to record detail. The more megapixels a camera has, the more detail its images can contain and the more they can be enlarged without losing clarity. More megapixels aren't always necessary, however.
  • Memory Stick – Memory Stick is a memory format used primarily by Sony digital cameras. Memory Sticks are available in sizes up to 1 Gigabyte.
  • Movie Mode - Movie mode lets digital cameras shoot video clips. Some cameras offer sound, while others can only take silent videos. The maximum length of a movie is determined by a camera's internal limits and/or the size of the memory card.
  • NiMH – Nickel Metal-Hydride: a type of rechargeable battery that can be recharged many times. NiMH batteries provide sufficient power to run digital cameras and flashes.
  • Optical Zoom - Optical zoom magnifies the size of an image by adjusting the lens. Unlike digital zoom, optical zoom enlarges the subject without sacrificing resolution.
  • Panning – A photography technique in which the camera follows a moving subject. Done correctly, the subject is sharp and clear, while the background is blurred, giving a sense of motion to the photo.
  • Pixel – Picture Element: digital photographs are comprised of thousands or millions of them; they are the building blocks of a digital photo.
  • Point and Shoot – A point and shoot camera offers few or no manual controls and very simple operation. Focus, exposure, and most other adjustments are completely automatic; all the owner needs to do is aim and push the shutter button. Most advanced cameras also have point and shoot modes.
  • RAW – One of the image formats available on some advanced digital cameras. RAW images are large, usually uncompressed files that, unlike JPEGs, are not processed by the camera and retain all their original data. RAW images are ideal for those who plan on editing their pictures with image-editing software. RAW images may require special software to turn them into a more common format like TIFF or JPEG.
  • Redeye – Redeye is the term used to describe the red color often visible people's eyes when a picture is taken with a flash. Redeye is caused by the reflection of the flash off the subjects' eyes -- a problem that is compounded when the flash is positioned close to the lens, as it is on many small cameras.
  • Redeye Reduction – By firing the flash several times just before exposing a photo, cameras with a redeye reduction feature cause a subject's pupils to contract, reducing the reflection that causes redeye.
  • RGB – Red, Green, Blue: the three colors to which the human visual system, digital cameras and many other devices are sensitive.
  • Saturation – How rich the colors are in a photo.
  • Sensitivity – See ISO speed.
  • Sharpness – The clarity of detail in a photo.
  • Shutter speed – The camera's shutter speed is a measurement of how long its shutter remains open as the picture is taken. The slower the shutter speed, the longer the exposure time. When the shutter speed is set to 1/125 or simply 125, this means that the shutter will be open for exactly 1/125th of one second. The shutter speed and aperture together control the total amount of light reaching the sensor. Some digital cameras have a shutter priority mode that allows you to set the shutter speed to your liking. See also aperture.
  • SLR Camera – The most expensive of all digital cameras, digital SLRs offer complete manual control, higher resolution, advanced exposure control, and the benefits of detachable lenses. Due to the lens design, digital SLR's are not capable of shooting video.
  • SLR-Style Camera – With protruding lenses and large hand grips, SLR-styles cameras have bodies that are physically similar to actual SLR cameras. Unlike proper SLRs, however, these cameras do not have "through-the-lens" viewfinders and do not accept interchangeable lenses.
  • SmartMedia – A digital camera memory format currently used by some Olympus and Fuji cameras. These companies are using xD-Picture cards in their newer cameras, raising the possibility that the SmartMedia format is on the way out. SmartMedia cards are available in sizes up to 128MB.
  • Thumbnail – A small version of a photo. Image browsers commonly display thumbnails of photos several or even dozens at a time. In Windows XP's My Pictures, you can view thumbnails of photos in both the Thumbnails and Filmstrip view modes.
  • TIFF – Short for Tagged Image File Format, TIFF is an image file format that does not lose any quality when it is saved and compressed. Many advanced cameras offer a TIFF format option.
  • Ultra Compact Camera – Ultra compact cameras are generally one inch or less thick, and small enough to be held in the palm of a hand. While these cameras do not offer all the manual controls of larger models, they still are capable of producing high quality images.
  • White balance – A function on the camera to compensate for different colors of light being emitted by different light sources.
  • xD-Picture Card – Released in Early 2002 by Olympus and Fuji, xD-Picture Card is the newest digital camera memory format. Physically smaller than all other memory formats, and available (as of 5/03) in sizes up to 256MB, the xD-Picture Card appears poised to replace the older SmartMedia format.

Resources
http://www.microsoft.com/windowsxp/using/digitalphotography/glossary/default.
http://www.digitalcamera-hq.com/hqguides/glossary-info.htmlmspx
http://www.pcphotoreview.com/Learn^digitalglossarycrx.aspx
 
Good list. I noticed one spelling mistake, the entry for Megapixel is spelled Megapixe.


Thanks for taking the time to write all that out.
 
Good stuff already. Some additions and comments, if I may.
  • SLR (addition) - the reason SLRs are called single lens reflex cameras is due to the fact that it uses a mirror that reflects the image seen through the lens into the viewfinder. This setup means the sensor is bypassed, which would explain why you can't use SLRs to record video or why you can't use their LCDs to preview a picture before it's taken. However, this setup allows you to see the same image the lens sees.

    dSLRs also have larger sensors compared to normal compact digital cameras. A large sensor means larger photo receptors, and the large sensor allows SLRs to use higher ISOs like ISO1600 or ISO3200 with less grain in the resulting picture than with a compact digital camera.
  • Bokeh - the quality of how out of focus points of light are rendered in the resulting image. Bokeh is dependent on the lens.

    Bokeh is easier to understand with pictures instead of words.
    http://www.kenrockwell.com/tech/bokeh.htm shows some examples of bokeh.

    Also see these images and look at the out of focus areas and how they're rendered.
    http://www.luminous-landscape.com/images18/bokehinpics.jpg
    http://www.msgaddict.com/images/flowers.jpg

    Not necessarily good bokeh (I took the second one, the bokeh is pretty bad I think), but bokeh is subjective. Some lenses are known for good bokeh, some are known for average bokeh, etc.
  • Depth of Field (DOF) - the planar area in the image that is in focus. Depends on factors such as aperture. Large apertures such as F/1.4 will produce an image with less DOF than an image taken at the same settings but with aperture at F/8, for example.

    As such, limited DOF is desirable for images such as portraits.
  • Flash sync speed - The shutter speed that is in synchronization with the flash speed. Most dSLRs (like the Canon DSLRs and some Nikons) have a flash sync of 1/250 second. Some (like the D70/D70s/D50 from Nikon) have flash syncs of 1/500 second.

Sources:
http://en.wikipedia.org/wiki/Single-lens_reflex_camera
http://kenrockwell.com/tech/2dig.htm
http://opd.usa.canon.com/html/eflenses/lens101/glossary/index_l.html
http://www.nikonians.org/html/resources/photography-glossary.html
http://www.luminous-landscape.com/essays/bokeh.shtml
 
havent forgot about this - just work been hectic, but will try to get things updated soon!
 
wow, this is old completely forgot about this section of the forum!

will see if i can get things a little newer.
 
MrGuvernment said:
wow, this is old completely forgot about this section of the forum!

will see if i can get things a little newer.
Click to expand...

Needs updates. :) One thing in particular that you may want to add is a definition of metering.
 
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