| Rubber Stamp | A tool used for replicating pixels in digital imaging. Also called Clone Stamp Tool |
| RS232 | Early digital cameras used RS232 (serial) connections for transferring data to external devices (PC's) |
| Royalty free | a term stock photography agencies use to denote that an image is licensed for multiple use. Usually a eupemism for shots the agency can't sell. Avoid this like the plague! |
| RMS | The square Root of the Mean Squared. The RMS of an alternating voltage or current the equivalent steady (direct) voltage or current which will have the same heating effect. |
| RLE | (Run Length Encoding) Lossless compression; supported by some common Windows file formats. |
| RIP | (Raster Image Processor) A processor (like a CPU) included in an output device that converts an image’s data into the dot pattern. It is this dot pattern that is printed onto film or paper. |
| rights managed | a term stock photography agencies use to denote that an image is licensed for one specific use only |
| RGB | Red, green, and blue the three primary colors and color space used by film and monitors. |
| RF | Radio Frequency |
| Reversal Processing | The process in which film is exposed so that it will become a positive instead of a negative or a negative instead of a positive. |
| Reversal Film | Positive (i.e. slide) film. Film in which the original negative image is reversed during the development process to produce a positive transparent image. |
| Reticulation | Simulates the controlled shrinking and distorting of film emulsion to create an image that appears clumped in the shadow areas and lightly grained in the highlights. |
| Resolution | Resolution is the term used to describe the amount of data in a file, screen display, or printed image etc. |
| Resistance | All electrical conductors (except superconductors) have some resistance, which means that they convert electrical energy into heat. A resistor is simply a device for which the property of resistance is accurately characterized. |
| Resampling | refers to changing the pixel dimensions (and therefore display size) of an image. When you downsample (or decrease the number of pixels), information is deleted from the image. When you resample up (or increase the number of pixels), new pixels are added based on color values of existing pixels. You specify an interpolation method to determine how pixels are added or deleted. |
| Registration marks | When printing, these marks are used to print marks on the image for alignment on the press (bull’s-eyes and star targets). |
| Refractive Index | Value for refraction of a material |
| Refraction | The bending of rays of light as they pass from one medium into another, e.g. from air to water, or from air to glass. |
| Reflector | A surface used to reflect light in order to fill shadows |
| Red Eye | When light from a flash reflects back from the pupil of subjects' eye it creates an unattractive red spot. A camera with a red eye reduction feature fires a pre flash a thousands of a second before the real flash to make the subjects pupils close. |
| Record | Capturing audio or video onto videotape |
| reciprocity | refers to the inverse relationship between the intensity and duration of light that determines exposure of light-sensitive material. Within a normal exposure range for film stock, for example, the reciprocity law states that exposure = intensity × time. |
| Rebikoff Port | A lens that corrects for refraction at the airwater boundary on an underwater camera, characterized by a flat surface in contact with the water and a concave surface in contact with the air. |
| Ready Light | LED indicator that lights when the flash unit is ready to fire |
| Raw Camera | an applicastion that ships with CS for processing RAW files |
| RAW | RAW files contain the same data captured by the CCD with no processing by the camera. This requires a ‘plug in’ for your image editing software to be able to open them. |
| Rasterize | Converting vector data to raster data. Performing this conversion is called rasterizing. |
| Rasterisation | The conversion of a vector based graphical representation into an array of pixels. |
| Raster | The rectangular area of illumination formed on a TV screen by the scanning process. An array of lines or dots of varying brightness which, when viewed from a suitable distance, produces the illusion of an image. |
| rangefinder | a simple window in the camera or accessory on top that approximates the coverage of the lens for framing composition |
| RAM | Random Access Memory |
|