Want to take your image files to the next level? Shooting in RAW format is key. JPEG files don’t make use of the vast majority of the information that modern camera sensors are able to record. RAW files do, and that translates into much more control in post-processing and higher-quality final files.
If you’ve ever geeked out on camera specs, you’ve probably heard the term “bit depth.” A bit is a small package of digital information that can have two possible values — a 0 (black) or a 1 (white). If we have a bit depth of two bits, we now have four possible brightness value combinations (00, 01, 10, 11 — there are now some gray tones in between the black and white). JPEGs are eight-bit files, which means there are now exponentially more combinations available to describe the potential brightness or luminance tones in an image. If we raise two to the eighth power, we get 256 possible brightness values. However, most of the cameras we use these days for nature and wildlife photography can capture RAW files with 14 bits of color information. Using the same math as above, we take two to the 14th power, and we have 16,384 possible brightness values for each pixel.
If our camera sensors captured only brightness values, we would all be shooting black-and-white photos. Thanks to the Bayer RGB filter that sits on top of the sensor’s photosites, however, we are able to capture color. How this really works is beyond the scope of this email and way beyond the scope of my expertise. In any case, since there are three color channels (red, green, and blue) in each of our camera sensor’s pixels, we can start to transform those original brightness values into the colors we see in nature. So, for our eight-bit JPEG file, we can next take 256 to the third power, which yields a total of around 16.7 million possible color values. Sounds good, right?
But combining all three channels in a 14-bit RAW file yields more than four trillion color value possibilities. If you shoot JPEG, you’re only using about 00.00038 percent of the possible colors that your expensive camera is capable of recording. A 14-bit RAW file contains more than 250,000 times as much potential color information as a JPEG file!
Those are some big numbers. But human eyes generally can discern only a few million different colors at best. Why does having more brightness and color information matter to us as nature photographers? Most pros and serious students of photography want to be in control of how their images look when they go up on the web, on the wall for a big print, or out to a magazine or book editor. You paid lots of money for your camera and its fancy digital sensor! RAW files take advantage of your camera’s sophisticated image-capture capabilities and allow you to stay in control of optimizing your images in the computer. As such, RAW files offer three primary benefits when compared to JPEG files.
First, RAW files allow you to take full advantage of the dynamic range of your camera’s image sensor. This means you can open up dark shadow areas and recover bright highlights to an incredible degree in the computer. This was a great help for one of my favorite recent shots, seen at the top of this email: a Talamanca hummingbird (Eugenes spectabilis) pollinating a native thistle flower in the highlands of Costa Rica. By shooting RAW, I was able to expose for the bright sunset sky in-camera and then lift the shadows of the surrounding cloud forest in the computer (two flashes lit the flower and hummingbird). If I had shot in JPEG, the shadows would have been a noisy mess when I brightened them in Adobe Lightroom.
Second, RAW files are less susceptible to posterization. This effect can become quite noticeable when working on smooth areas of an image with subtle tonalities, such as the sky or the background. With JPEG files, post-processing adjustments will start to reveal abrupt edge artifacts that resemble a pointillist painting. By way of example, I intentionally shot through some dense foliage last year in Costa Rica for the portrait of the resplendent quetzal (Pharomachrus mocinno) above. Even though I manipulated the background tones of the photo in Lightroom, the massive amount of information from my RAW file kept the bokeh looking cool yet artifact-free.
And third, many wildlife and bird photographers employ huge crops back at the computer (seriously, you wouldn’t believe the original RAW files behind some of those “frame-filling” bird portraits we see out on the Internets!). I’m not a fan of cropping heavily, and I’ll touch on an alternative strategy for those big-crop scenarios in an upcoming article for the Journal. Nonetheless, RAW files certainly give us more cropping freedom while retaining great image quality. This also applies to enlarging photos for big prints. I processed the below photo of a southern lapwing (Vanellus chilensis) from Panama as both an eight-bit JPEG and as a 14-bit RAW file. To exaggerate the point, I cropped in quite a bit, enlarged the file, and then made some heavy-handed adjustments. The differences won’t always be this apparent, but this example makes clear the types of advantages that RAW files offer.
While RAW files help us to squeeze the most out of our camera’s sensor, they have some drawbacks. RAW files are bigger, so we’ll fill up our cards more quickly and will need more storage space. And RAW files are made to be post-processed. JPEG files often look vibrant and punchy right out of the camera; RAW files, not so much. When you shoot RAW, you’ll spend more time at the computer learning how to use software such as Lightroom and Photoshop and processing your images.
If you don’t enjoy spending time at the computer, rest assured that photos captured in JPEG format can in fact produce nice image files. And to be honest, you often may not even notice the difference between files captured in eight bits vs. 14 bits. The most important part of photography is our technique and persistence and enjoyment in the field. But, if you’re working hard and want to present the absolute best-quality versions of your favorite images for a wide range of uses from social media to gallery prints, shooting RAW will put you on the path to success!