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R

RAM - Random Access Memory . The most common type of computer memory; where the CPU stores software, programs, and data currently being used. RAM is usually volatile memory, meaning that when the computer is turned off, crashes, or loses power, the contents of the memory are lost. A large amount of RAM usually offers faster manipulation or faster background processing.

Rangefinder - The viewfinder on most cameras is a separate viewing device that is independent of the lens. Often mounted above and to the right or left of the lens. It exhibits a problem known as parallax when trying to frame subjects closer than five feet from the camera so it is advisable to use the colour LCD when shooting closeups for this very reason.

RAW - RAW files basically hand the raw unprocessed data - at 12 bits per channel - from the camera’s imaging chip to your computer. Lossless compression is applied to reduce filesize slightly without compromising any quality.

Red-Eye - An effect caused by an electronic flash reflecting off of the human eye and making it look red. Compact cameras with the flash located close to the lens suffer the worst from this problem. Pro photographers use a bracket to hold an external flash unit above and off to the side of the lens to eliminate red-eye.

Red-Eye Reduction Mode - A special flash mode whereby a pre-flash or a series of low-powered flashes are emitted before the main flash goes off to expose the picture. This causes the pupil in the human eye to close and helps eliminate redeye.

Render - The final step of an image transformation or three-dimensional scene through which a new image is refreshed on the screen.

Resize - Usually means to take a large image and downsize it to a smaller one. Most graphic viewing and editing programs offer a Resize option for this purpose.

Resolution - The quality of any digital image, whether printed or displayed on a screen, depends in part on its resolution—the number of pixels used to create the image. More and smaller pixels adds detail and sharpens edges.
l Optical Resolution is an absolute number that the camera's image sensor can physically record.
l Interpolated Resolution adds pixels to the image using complex software algorithms to determine what colour they should be. It is important to note that interpolation doesn't add any new information to the image - it just makes it bigger! Camera makers often specify the resolution as: QVGA (320 x 240), VGA (640 x 480), SVGA (800 x 600), XGA (1024 x 768) or UXGA (1600 x 1200)

RF - Range Finder - a type of camera viewfinder that uses one lens to frame your subject and another lens to capture the image. See "SLR" for the other type.

RGB - Means Red, Green and Blue - the primary colours from which all other colours are derived. The additive reproduction process mixes various amounts of red, green and blue to produce other colours. Combining one of these additive colours primary colours with another produces the additive secondary colours cyan, magenta and yellow. Combining all three produces white.

RS-232 - Standard type of serial data interconnection available on most PC type computers. It's the slowest way to transfer image data from a camera. Most digicams made after 2001 do not have serial ports any more, they now use USB.

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