I’ve recently fielded some questions about XMP sidecar files in Adobe Lightroom and felt that would be a good topic for this weeks blog post. Before we get into XMP sidecar files and Lightroom, let’s first explain why they are needed. Lightroom is a non-destructive image editor, meaning that it does not alter the original RAW image in any way save for renaming the file. Hence Lightroom, as well as Photoshop CS2 and CS3, both use what are called XMP sidecar files that describe the changes and additions applied to a RAW image. These include the addition of metadata, all of the adjustments made in Lightroom or Adobe Camera RAW and any other adjustments or alterations added such as keywords and the like.
Hence, in Lightroom, the XMP sidecar files contain the metadata, keywords and adjustments made to an image. In its default mode, Lightroom does not automatically write these sidecar files into the folder containing your images. You have to go into the preferences and check the “Automatically write changes into XMP” box to turn this feature on as in the image below.
Once you have this box checked, Lightroom will create XMP sidecar files that show up in the same folder along with your images and with the same name as the RAW image file but with an .xmp file extension.
Now, I know many of you are asking why would I want to do this? When you import images into Lightroom all of the changes, metadata and keywords are recorded in the Lightroom cache while working on your images so additionally saving this information into the folder with your images might seem redundant. My reasoning for doing this is partly my archival strategy and partly for convenience as well as how my workflow works.
I want to have the XMP sidecar file next to my RAW image file in the same folder because I want that information to travel with the RAW file wherever it goes. After I have backed up my images to two hard drives I also burn them to DVD’s - my third back up. I have had two occasions where I’ve had to reload images from those DVD’s (my third backup) and I was very glad to have the XMP sidecar files right there so I did not have to redo all of the work I had done before. This is a huge advantage to having the XMP sidecar files in with my RAW images.
Another convenient reason for using the XMP sidecar files is transferring images I have partially worked up on my laptop to my office computer for final prep. I can just copy a group of images along with the Lightroom XMP sidecar files onto a hard drive, dump them onto my main imaging computer, then import them into Lightroom and voila, all of my settings and everything are read by Lightroom and I can continue working without missing a beat because Lightroom reads those settings from the XMP sidecar files.
And finally, my workflow is such that I don’t import all of my folders into Lightroom and leave them there indefinitely. I bring folders in that I am working on, then after a month or two, I delete those folders out of Lightroom so that it stays snappy and fast. Hopefully soon, Lightroom will also become the end-all-be-all image cataloging and archiving software of choice but as of yet it is not. When it is, then I’ll leave all of my folders and images in Lightroom.
That’s it for this week.
Adios, Michael Clark