RAW image format

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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.

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.