RAW image format

A proprietary digital camera format that contains all the pixel information captured by the camera's sensors. RAW formats give the photographer complete flexibility and artistic control to create the best result. Although the camera processes the captured image based on the ISO, shutter and aperture settings, the sensor data have not been interpolated, encoded and compressed into a standard such as JPEG or TIFF (see Bayer pattern).

There are numerous proprietary RAW formats (see below), and except for Adobe's DNG, most general-purpose image editing applications do not recognize them. Camera vendors provide their own software for editing, importing and converting their proprietary formats. See DNG image format.

Post Processing Advantages
Because the format processing is bypassed, photographers have the freedom to make their own adjustments in the studio later on. Attributes such as hue, saturation, white balance and contrast can be adjusted using a RAW editor before the sensor data are turned into RGB pixels. Even the exposure can be altered with better results. RAW formats also offer 12 or more bits of color depth, and changes can be applied to the full color range before they are reduced to 8 bits in JPEGs and TIFFs.

In addition, a RAW file can always be converted into a different format, which is why RAW images are called "digital negatives." Like old film negatives, the original can be used over and over to make different photos, each with its own alterations. The only real drawback of RAW photography is the time it takes to do the post processing. See graphics formats. See also RAW file system.

RAW CAMERA FORMATSVendor File Extensions Adobe DNG Agfa MDC Arriflex ARI Canon CR2, CRW Casio BAY Epson ERF Fuji RAF Hasselblad 3FR, DNG Imacon FFF Kodak DCR, DCS, DRF, KDC, K25 Konica MRW Leaf MOS Leica RAW, RWL, DNG Logitech PXN Mamiya MET Minolta MDC, MRW Nikon NEF Olympus ORF Panasonic RAW, RW2 Pentax PEF, PTX Phase One CAP, LIQ, EIP Ricoh DNG Samsung SRW, DNG Sigma X3F Sony SRF, SR2, ARW

RAW Adjustments

This illustration combines two dialogs from Photoshop Elements to show the many adjustments that can be made to RAW images.