RAW image files are a great tool for professional photographers, offering flexibility, editability, and portability. For these reasons, we encourage all our post-production clients to consider the RAW+XMP workflow when using Post services. Here’s an overview of how it works.
What is RAW?
RAW is a generic term for the multitude of proprietary image file formats created by camera makers. Most photographers will be familiar with “CR2″ and “NEF”, which are the Canon and Nikon RAW formats, respectively.
The RAW format is an alternative to JPG. The biggest benefit RAW has over JPG is the amount of image information it contains. RAW files hold all the data captured by the camera’s sensor, allowing you to later process the image with a wide range of flexibility. JPGs, on the other hand, are a result of processing that happens in-camera, and much of the data is thrown out to save on file space.
If you’re looking to edit your images after the shoot, RAW is much more lenient when it comes to changing white balance, adjusting exposure, and recovering image data in the highlights and shadows.
RAW files also have a unique workflow aspect to them: XMP files. XMPs are crucial to the RAW+XMP workflow, so we’ll spend some time explaining these little guys.
What is an XMP?
For each RAW file you edit, you will have an associated XMP file. The RAW file is usually big and holds the actual image, while the XMP file is tiny and holds data about the image.
What kind of data? Different kinds, but instructions are what we’re most interested in. When changes are made to an image in a program like Adobe Lightroom, those changes are not actually applied to the RAW file itself — the RAW file always stays untouched so we can go back to the original if needed. Instead, the changes are saved separately as a series of text instructions (think along the lines of “raise saturation by 5″), and these text instructions are — you guessed it — XMPs.
So, we now have one XMP file for each RAW file. Of course, just opening an XMP file isn’t going to tell us humans anything useful. We need to give the RAW and XMP files to a program which can combine them and display an edited image. At Post, we use and highly recommend Lightroom.
- Nothing set in stone
As we mentioned, the RAW file is never modified. All the changes are saved separately for you to accept, reject or add on to. Think about the alternative: If you start with a JPG file, edit it in some way, and then save the changes, you’ve lost the original image and have no way of going back.
- Easier archiving
After realizing your mistake in the above JPG example, you start making sure to always save JPG changes as a new file. Great, now you have the original and the edited files, but they’re both about the same size: big.
With the RAW+XMP workflow, however, you have the benefit of keeping the original image and the changes — the difference being that the changes (the XMPs) are very small files, so you’re only storing one big file instead of two. This helps reduce the amount of storage space needed for archiving your images. Plus, the original image and the changes are conveniently stored together in the same folder.
- Faster turnaround
Next, consider using a post-production editing service like Post. Say you decide to send in the RAW files for a wedding you shot last weekend. The files are big and it takes a while to transfer, but it’s worth it. If only there was some way, once the images are corrected, we didn’t have to take the time to send all those files back to you.
Enter XMPs. Once we’ve corrected your images, there’s no reason to send the RAW files back — they haven’t changed! Instead, you can have your changes returned quickly — usually a download of a few seconds — because all you need back are the XMPs.
Putting it Together – The RAW+XMP Workflow
Now that you know what RAW images are and what their sidecar XMP buddies are, it’s time to put them together into a RAW+XMP workflow. There are many variations on the following, but we’ll keep it simple for now and recommend the following.
- Before the shoot, set your camera to the RAW setting.
- Shoot like normal.
- After the shoot, copy the RAW files over from your camera, and back them up.
- Send the RAW files to your editor (Post, right?). If you prefer to do your own image selection, just send the keepers.
- Go make money while your editor works on the images.
- Receive XMP files back from your editor.
- Combine the returned XMPs with the original RAW files (more info on that below).
- Review the edits, then either continue to work on the images yourself or export them to JPG for printing and web upload.
Pretty straightforward, huh? Well, there’s always more to learn, so we’ve provided a few other articles on the topic below.
- We offer a few variations on the RAW workflow in this article as well as help you make the transition from shooting JPGs to shooting RAW.
- Learn how to sync XMPs with your RAW files using Lightroom. We offer a video tutorial as well as a write-up.
- Maybe you’ve heard about DNG files? We’re not big fans, but here’s an introduction to DNGs.