RAW Files vs JPEGs
RAW files are your digital negative. Like film negatives, RAW files contain the greatest range of visual information and offer the greatest latitude in post-production. RAW files are uncompressed, unlike the highly compressed jpeg file, which discards information to reduce file size. Once that information is lost, it cannot be retrieved. RAW files offer a much greater dynamic range (the ratio of brightest tones to darkest tones) and allows for greater detail in both highlights and shadows. An 8-bit RAW file contains 16.8 million possible colors, whereas a jpeg contains a mere 256 colors. That is fine for web images, but unacceptable when printing or publishing images.
RAW files require a RAW converter such as Adobe Camera Raw or Capture One Pro. I have used both, and while there is an argument for each, I choose to use Adobe CC because it is what I am most familiar with, and also I use other programs in the Adobe Suite like InDesign and Premiere Pro.
8-Bit or 16-Bit Depth
As previously mentioned, an 8-bit image contains 16.8 million possible colors, which would seem more than adequate when printing an image, but there are situations in which tonal differences are so subtle that even this many colors doesn’t produce a smooth transition. This step from one tone to the next can create a noticeable effect known as banding. Saving the processed file as a 16-bit image produces a staggering 281 trillion colors and greatly reduces the incidence of banding. This is beneficial in rendering smoother and more subtle tonal transitions in large continuous areas such as a blue sky. Be aware that a 16-bit file is twice as large as its 8-bit counterpart. Save your optimized image as an uncompressed TIFF file.
Why Convert to DNG Files
RAW files are proprietary to the particular make of camera in which they are shot. Canon RAW files (CR2) are different than Nikon’s (NEF), which are different from Olympus files (ORF). As software continues to evolve, these various formats eventually become obsolete and unusable. The DNG format is Adobe’s attempt to standardize the RAW file so that it can always be opened regardless of a camera’s make or when the file was created. Whenever I work with a RAW file, I convert it to a DNG file and save it in its own folder. That way, I have a workable file ten or twenty years down the road.
I prefer to shoot RAW files + large jpegs (See your camera manual). This gives me a ready-to-use image right out of the camera that I can immediately send to a client if necessary without having to post-process the photograph. It also aids me in making early editing decisions, such as eliminating out-of-focus shots or comparing image composition. Always strive to properly expose the image in-camera. Meter using an 18% gray card, then bracket. This will greatly reduce the amount of time you spend optimizing an image—and that equates to more time in the field actually creating photographs. Backup all your files regularly. Redundancy is king. Store your files on multiple hard drives (at least two), and store one of those devices off-site to protect you, heaven forbid, from fire or natural disaster. A safe deposit box is optimal.
I hope you find this article informative—and if you aren’t already shooting in RAW format that it has convinced you to start doing so.
Please contact me with any questions, comments, or suggestions. Until next time, happy image-making!