|Top Previous Next|
Most professional cameras have a raw image format available in addition to the normal JPEG and TIFF formats.
A RAW image file contains minimally processed data straight from the image sensor of a digital camera or image scanner. Raw files are so named because they are not yet ready to use by a bitmap graphics editor and cannot be printed or displayed by a normal web browser. The image must be processed and converted to an RGB format such as TIFF or JPEG before it can be manipulated.
Raw file formats are becoming extremely popular in digital photography workflows because they offer professionals greater creative control. However, cameras use many different raw formats — the specifications for which are not publicly available. This means that many raw file formats may be unreadable by any specific particular software application. As a result, the use of such proprietary raw files as a long-term archival solution carries risks. There is no guarantee, for example, that you will be able to find a computer that can read a Canon RAW format in, say, 10 years time. Sharing these files across complex workflows is even more challenging.
DNG (the Digital NeGative) format is a publicly available archival format introduced by Adobe for the raw files generated by digital cameras. By addressing the lack of an open standard for the raw files created by individual camera models, DNG helps ensure that photographers will be able to access their files in the future.
A second benefit of DNG format is the ability to save all the picture information contained in the proprietary raw files’ sidecar XMP files (keywords, description, copyright notices) directly into the DNG file. There is no longer any need to worry about sidecar files. They cannot get lost or disassociated from the image.
Another benefit of DNG is the ability to store a full-size or medium-size JPEG preview file. This allows for third party photo management software such as PicaJet to directly use the preview file instead of slowly parsing a large RAW file to display a preview image.
Adobe also provides a small utility for easy conversion of camera RAW files to DNG format.
Read more about RAW files: http://en.wikipedia.org/wiki/Camera_raw