OCR (OPTICAL CHARACTER RECOGNITION)

Definition: A technology that allows dots or pixels within characters inside a bitmapped image to be converted into an ASCII text file. This text file can be edited.

Definition: Software that allows the computer to convert documents that have been scanned and saved in a graphics format back into editable text.

OFF-THE-FILM METERING

Definition: A meter which determines exposure by reading light reflected from the film during picture-taking.

OFFSET PRINTING (OFFSET LITHOGRAPHY)

Definition: A common printing process that makes prints by transferring ink to a rotating "blanket" that contacts the paper.

ONE-SHOT DEVELOPER

Definition: A developer used once and then discarded.

ONLINE PHOTO PRINTER

Definition: A company that receives digital photos uploaded to its Web site, prints them, then sends the prints back by mail or courier.

ONLINE SERVICE

Definition: A commercial service that gives computer users Internet access and connection to a variety of online offerings, such as shopping, games and chat rooms.

OPACITY

Definition: The degree to which an object blocks light. Technically, opacity is expressed as a ratio of the incident light to the transmitted light.

OPAQUE

Definition: Describes
1. any substance or surface that will not allow light to pass;

2. a paint used to block out portions of a negative so that they will not allow light to pass during printing.

OPEN UP

Definition: To increase the size of a lens aperture. Opposite: stop down.

OPENING UP

Definition: Is increasing the size of the lens aperture or decreasing the shutter speed to admit more light to the film.

OPTICAL AXIS

Definition: Is an imaginary line passing horizontally through the center of a compound lens system.

OPTICAL DISK

Definition: A digital storage system commonly used for mass storage.

OPTICAL FILTERING

Definition: Selectively transmitting or blocking a range of wavelengths of light. See filter

OPTICAL FREQUENCY RESPONSE

Definition: A scanner's capability for capturing a given frequency or range of frequencies.

OPTICAL RESOLUTION

Definition: The true resolution of a scanner and the key factor in determining the amount of detail visible in a image. Optical resolution is one type of resolution; the other is interpolated resolution.

OPTICAL SCANNER

Definition: A device that changes images from either reflection or transparency medium to digital data.

OPTICAL STORAGE

Definition: A peripheral device for storing data. It may be WORM or rewritable.

OPTICAL VIEWFINDER

Definition: A viewfinder system that shows a similar view to that seen by the camera lens ( as on 35mm compact cameras ) Useful because it uses no power, but can cause parallax and focus errors.

OPTICAL ZOOM

Definition: An optical zoom is made to bring you closer to your subject, without you having to move. Zooms are constructed to allow a continuously variable focal length, without disturbing focus. To achieve this, the optical zoom uses a combination of lenses that magnify the image prior to being registered at high resolution by the sensor. While the digital zoom only changes the presentation of existing data, the optical zoom actually augments the data collected by the sensor. Optical zooms are superior to digital zooms.

ORTHO (ORTHOCHROMATIC)

Definition: Denotes film sensitive to blue and green light.