What is RAW Photography?

Everything you need to know about RAW images

A photographer studying his camera.

 @esspeshal via Twenty20

RAW photography refers to shooting photographic images in an uncompressed format called RAW. You may also hear this referred to as camera raw; it means the image is unprocessed or minimally processed by your camera, so all the original image data remains intact. For post-processing purposes, this is the best possible format you can use when taking digital pictures.

Why Should Your Use RAW Images?

If you’re new to photography, you may not understand all the fuss about RAW images. What makes them so great? The short answer is because a RAW image maintains all the data captured by the image sensor of your camera. But a longer explanation may be better.

When you take a picture with your DSLR camera, the image sensor captures light, shadow, and tones of colors for the length of time your shutter is open. That information is captured in pixels, or small squares. It’s what happens after the shutter opens and closes and image sensor captures that data that determines the file format your camera outputs.

A RAW photo and a JPEG photo side by side.

If you’re capturing images in JPEG format, which is one of the default formats for most digital cameras, once the image has been captured, the camera processes it to determine which pixels to keep, and which are redundant and unneeded. It also makes some adjustments for you that cannot be changed once the image has been processed and the unused pixels discarded. The result is an image that looks like what you captured, but it contains less of the information the image sensors captured. It’s great for sharing photographs, since the images are smaller and easier to manage, but if you need to make tweaks or changes to the image in post processing, it’s not ideal.

When you capture images in RAW format, the image data captured by the image sensor — light, shadows, and tones of color — is left unchanged and uncompressed. The camera doesn’t determine which pixels to keep and which to discard and it doesn’t make adjustments; it leaves the image as-shot so you can decide what’s valuable, what’s not, and what needs to be changed or adjusted.

Shooting in RAW and RAW File Extensions

Most digital cameras are set to capture JPEG images by default. If you want to shoot in RAW, you’ll need to make the adjustments in your camera to change to RAW format. You’ll find these options in your camera’s Settings menu, usually under an option called Quality or File Format.

Many cameras have the capability to capture RAW + JPEG. What this means is that the original, RAW image is stored, then the camera processes the image and stores a second version of it with the modifications and compression in a JPEG format. Since this gives you both the smaller format for sharing and the larger format for editing, many photographers choose to shoot with RAW + JPEG instead of one or the other.

Where things start to get a little confusing is in the file format that your camera outputs for RAW images. Most manufacturers use proprietary file extensions for RAW file. For example, a RAW file from a Canon camera will probably show up as a CRW or CR2 file, while a RAW file from a Nikon will show up as a NEF file. It’s rare that when you download the files from your camera, you’ll see the RAW extension, even though you are actually dealing with a RAW file.

To add one layer of complexity to mix, each RAW file is also accompanied by an XMP (Extensible Metadata Platform) file. This is the file that contains data about all the adjustments that are made to the file. In most cases, you won’t ever see this file on your computer, because software today is smart enough to hide it. But it is there, and each time you make a change to the image in post processing those changes are saved in the XMP file.

Of course, RAW images are much larger than JPEG images because they contain more data. Some photographers may choose a JPEG format intentionally to be able to capture more images on a single SD card. While this makes sense, the availability and pricing of SD cards today it makes more sense to capture images in RAW and exchange the SD card for a new one if it gets full.

How Do I Process a RAW Image?

One capability you will lose if you choose to shoot in RAW may be any camera-enabled special image filters or settings. That’s because those special filters and settings require the camera to store the final image, with whatever processing you’ve selected in JPEG format. For casual photographers, this is fine. It’s easier (and probably a little more fun) to add an in-camera filter to an image and then immediately share it with family and friends.

One digital camera feature where this doesn’t hold true is the black & white setting. You can still shoot amazing black & white images on your camera, and even preview them in black & white, but if you’re shooting in RAW, when you upload those pictures to your computer, you will probably find both a full-color RAW image and JPEG black & white image. You may choose to shoot black & white pictures this way or to process them to black and white in post processing. That’s a choice that’s all your own.

However, the most important reason you’ll want to shoot in RAW is to maintain all the data in the image so you can use post processing to create your own style. Unfortunately, not all photo editing applications will process RAW images. However, there are several them that will:

Once you open your image in one of these applications, you can adjust everything from the exposure of the image to the hue and saturation levels, brightness and contrast, and much, much more. And since RAW format maintains all the data captured by the image sensor, you have control over the final outcome of the shot, which means you can add your own personal styling — something the camera might not be able to capture — to the image.