Painting the Web

Working with RAW Images

Unlike JPEG, GIF, or TIFF, RAW does not stand for anything other than an image that's stored in a "raw," unprocessed state. No compression routine is used, the data is not processed, and all camera sensor information possible is stored with the image.

The advantage to the RAW format is that you can modify certain characteristics of the image—exposure, color saturation, sharpness, white balance—after the image has been taken. About the only characteristics you can't change are ISO, aperture, and focal length of the picture—the characteristics of film, in fact.

The disadvantage of the RAW format is that the image files are quite large. However, with the multi-gigabyte memory cards nowadays, this isn't the issue it once was. My 4GB memory card can store over 200 photos, which is more than sufficient for my needs, and if it isn't I have additional memory cards on hand. Storing RAW data can also be slower, but not necessarily to the point where most of us would notice—especially with the increasing number of optimizations in today's digital cameras.

If all cameras supported the same RAW format, our lives would be so much simpler, but unfortunately they don't. As mentioned earlier, I have Nikon D200 and D70 cameras, and the RAW format Nikon supports is NEF. Canon supports CRW and CRW2 (Canon RAW); Sony's is SRF (Sony Raw Format). Rather than continue this proliferation of different formats, Adobe has proposed a RAW file standard: DNG, or Digital Negative. In addition ...