Ray Roper's Blog

I hadn’t planned to squander much ink on technical stuff in these entries, and the whole subject of RAW, as more experienced members know, has been done in copious detail on various Internet sites. Nonetheless, I’ve heard a number of comments and had questions at some of our meetings about shooting RAW--or not--that lead me to believe that maybe some members could benefit by revisiting the subject here.

First let’s specify right up front that RAW is really raw. It’s not an acronym, but just refers to the fact that the file format is the “raw,” or native, output of your camera’s internal digital process. The capitalization of the word is a convention to clarify a reference to a generic file type. And, in fact, there are several different RAW file formats used by different camera manufacturers. Canon’s is .CR2, Nikon’s .NEF, Olympus’ .ORF, and so forth. There is an open-source RAW format developed by Adobe called .DNG (Digital Negative) that is intended to overcome the digital Tower-of-Babel aspects of this fragmentation, and that has some potential to become the eventual standard. But the reality is that most any processing software you use, whether that be Lightroom, Aperture, or any one of a dozen or so commercial conversion and editing software packages, has the ability to handle all of the commonly used RAW formats. Each of the camera manufacturers offers a free (and relatively primitive) conversion utility that will convert its camera RAW files to JPEG or other more universal formats like TIFF.

So you might well ask, “why do I need to convert?” and maybe more to the point, “why bother?”

The default format for all point-and-shoot cameras, and most DSLRs as well, is JPEG (an acronym for the Joint Photographic Experts Group, the industry committee that  promulgates the standard). It is often shortened to .JPG to fit the earlier Windows standard for file name extensions. JPEG or TIFF formats are the ones most commonly used both for printing photos and for publishing them on the Internet, while RAW files cannot be (easily) used for either purpose, so the conversion is ultimately necessary.

So why bother? Well, the short answer is the power of your post processing capabilities will be enhanced literally by an order of magnitude if you shoot and edit RAW files.

JPEG is what’s called a “lossy” format, meaning that the file is compressed-- in-camera, if you’re shooting JPEG--from the original RAW format. The compression typically reduces the file size by three or four times. But with that compression comes a loss of information that was in the original file. That loss can be very significant. Just as an example, the JPEG standard records 8-bit, or 256 levels, of brightness. RAW, on the other hand, depending on which one you are using, records either 12-bit or 14-bit brightness, which equates to 4096 or 16,384 levels, respectively.

Your camera can’t see the fine gradations of brightness from deep shadows to bright highlights that your eye can, but it sure comes a lot closer in its native RAW format than it can when that is compressed to JPEG. The upshot is that your ability to recover details from deep shadows that appear completely black and from highlights that appear completely blown out is really quite astonishing in a RAW file if you are only used to working with JPEG. I find that I rarely need to shoot HDR or multiple exposures to get the range of brightness I need in most scenes, simply because it’s really all there in the RAW file. You just have to use your editing software to “dodge and burn” (brighten dark areas, darken overly bright ones) in order to bring out the richness of the scene that your camera was able to record.

Examples, SOOC  RAW file and after editing in Lightroom.

Brightness levels are not the only characteristic of image files that is greatly improved with  RAW files. Fine detail quality, continuous color gradations, white balance, and other features as well are all dramatically improved in the RAW image, simply because you are getting everything the camera is capable of without any loss.

There is a whole lot more to it than I’ve described here, of course. But in the interest of keeping this brief enough to avoid putting everyone to sleep (too late?), those who would like more detail on the subject should take a look at this very informative and comprehensive Rob Lim Blog on the subject and then follow up with his answers to questions generated by the first post.