The Oxford American Dictionary defines raw as: "Uncooked, a material or substance in its natural state; not yet processed or purified, information not analyzed, evaluated or processed for use." The definition of raw generated by the digital stills industry reads as such: A raw image file contains minimally processed data from the image sensor of a digital camera or image scanner. Raw files are so named because they’re not yet processed. Raw image files are sometimes called digital negatives, as they fulfill the same role as film negatives in traditional chemical photography—that is, the negative isn’t directly usable as an image, but has all of the information needed to create an image.
Like a photographic negative, a digital negative may have a wider dynamic range or color gamut than the eventual final image format. The selection of the final choice of image rendering is part of the process of white balancing and color grading.
So with such a straightforward definition, why is it that raw for motion pictures is so widely used, yet so undefined and misunderstood? Is it just a sound bite with no substance? Is it used to sell and market cameras? Or is it just semantics?
Within our industry, we have standards—defined standards that we all must accept to be the truth. These standards are defined within the parameters of the motion picture industry and are designed with the intent to be fit within an existing or developing workflow. Curtis Clark, chairman of the ASC Technology Committee, states, "All these cameras have to fit into a practical comprehensive workflow that can handle those images and maintain the creative intent and look that the filmmakers wanted to achieve."
The ASC has been trying its best to help define this new digital landscape, which is compared by others as that of the Wild West, or even anarchy. The ASC established the Technology Committee in 2003, led by veteran cinematographer Clark and joined by fellow ASC members. The goal of this collective brain trust, or the Data Mode Working Group as they call themselves, is to "assess and evaluate the impact of digital technology in the motion picture workflow," explains Clark, "to make suggestions as to how these technologies may best serve the creative needs of the filmmakers." Bill Hogan, an associate member of the ASC Technology Committee, has been given the task of actually writing the definition of raw for publication. He defines it as such: "The linear light image coming off of the sensor, no gamma correction, not log, with no processing in any way, no debayering, no compression."
I’m sure the final definition will be much more in depth, but for now this is what Hogan and the ASC are running with. I’ve spoken with manufacturing reps from Panavision, ARRI, Vision Research, Silicon Imaging, RED, DALSA and Thomson Grass Valley, and most concur with the definition to which Hogan is committed. However, it wasn’t a unanimous agreement across all parameters. Exceptions to these rules have already been argued in the name of technological limitations, inherent digital capture issues, as well as image-gathering techniques.