Adobe Camera Raw: Saving Conversion Settings
When you shoot a raw image in your digital camera, all the relevant settings used get recorded along with the actual image data. If you open that raw image in Nikon Capture or many other raw converters, the choices you set in-camera are used as the defaults for the conversion process. Not so with Adobe Camera Raw: it actually ignores most of the camera settings. Neither does it write any changed settings back to your raw file when you finish editing an image. So just what does ACR do with settings?
Perhaps because Camera Raw supports so many different raw formats, each of which has its own variety of settings that may differ widely in meaning from those of raw formats from other manufacturers, ACR takes an entirely different approach to things. While it does default exposure and white balance to your "as shot" choices, it doesn't even look at any of the others camera choices. Instead, it relies on its own defaults based on the camera make and model, although you can change those defaults. To do so, first adjust a representative image as you'd like it to appear. Then click on the small triangle at the top of the settings area and select "Set Camera Default." This way, if you find you often have to increase saturation or other settings, you can have this done automatically on all future images as you open them.
If you've ever noticed that your images look different in ACR than they do in Nikon Capture, it is likely because of this difference in what defaults each starts with that is to blame. Don't despair though. Once you tweak your ACR camera defaults to suit your fancy, you should be good to go.
Now let's look at where your settings go when you finish editing a file. One of the primary design rules of Adobe Camera Raw is to never make any changes to your actual raw files. This means that it has to save any changes somewhere else. If you are using the full version of Photoshop you have a choice between using what's called the "Camera Raw Database" and using something called "Sidecar XMP files." In Photoshop Elements, your settings will always go in the Camera Raw Database since it doesn't support Sidecar files.
The Camera Raw Database is a proprietary Adobe file that is hidden in the bowels of you computer and remembers what settings are used for each file. If you move your raw files around on your hard drive or even rename them, the Camera Raw Database can still figure out which settings go with which image since it relies on data recorded inside the file itself by the camera. This works great if you only work on a single computer and don't share raw files with others. It means that even though the settings aren't saved in your raw files, they always remember how you left things the last time you edited each image.
You might wonder where this mysterious Camera Raw Database actually lives. On Windows, it lives in a file called simply "Database" in the "Documents and Settings\<user>\Application Data\Adobe\CameraRaw" folder. On Mac OS 10, the file name is "Adobe Camera Raw Database" which can be found in "~/Library/Preferences." Not that you can do much with it outside of Photoshop of course.
If you use Photoshop on more than one machine or send raw files to others (and use Photoshop itself rather than Elements), you may prefer the alternative of using Sidecar XMP files. These are small text files written in an open XML-based standard called XMP (eXtensible Metadata Platform). The files are saved in the same directory and with the same name as each edited image, but with the .xmp suffix. So long as you use the Photoshop File Browser to move or rename your raw files, these Sidecar files will automatically go with the raw files they describe, but if you use other tools you may need to remember to move or rename them yourself or risk losing your settings. This isn't too difficult though given that they should appear right next to matching image files in a directory listing. If you send a raw file to someone else, you can also send them the matching XMP Sidecar file so they have the same settings you had.
It's beyond the scope of this article, but Sidecar files are also quite handy if you want to repurpose the EXIF or conversion settings data for your images. For fun sometime, open one of your own XMP files in Notepad or other editor and take a peek at what's there.
In Photoshop Camera Raw, to switch between using the Camera Raw Database and Sidecar files, go to the ACR Preferences by clicking on the same small triangle at the top of the settings area that we used to set the camera defaults previously. At the bottom of the same menu is the Preferences option (we used it last week to access the Sharpening preference option). The default for conversion settings if you've never changed it is to use the Camera Raw Database.
That's about it for settings in Photoshop Elements, but the full version of Photoshop gives you a couple of additional choices, also on that same pop-up menu. "Save Settings" lets you save a named collection of settings that can be used for other images by using "Load Settings" later. This lets you keep groups of presets without altering your camera default. As an example, imagine developing settings for the look of Velvia or some other film and being able to recall them as needed for other images. Nice. If you only want to include some of the settings, no problem since ACR also includes "Save Settings Subset" on that same pop-up menu.
Camera Raw is an extremely flexible tool for converting raw images. It does use a somewhat unusual design philosophy for settings that can take a bit of getting used to. Once you do though, you may find prefer it to fiddling with all those settings while you are out shooting.
Update 4/10/2005: By the way, something I probably should have mentioned by now is that Adobe has announced the new version of Photoshop, cleverly named Photoshop CS2. Included in the new version is Adobe Camera Raw 3.0, a significant upgrade to the current 2.x versions. While most everything we have talked about here these past few weeks remains the same, there are some very nice new features as well. Some of these include improved batch processing support, and the ability to do lossless rotations and crops. Due to the time lag required for pressing CD's and retail distribution, ACR 3.1 will also be available on Adobe's site at about the same time Photoshop CS2 ships. This will be a free download but will only be compatible with CS2 and Elements 3.0. Photoshop CS users will need to upgrade to CS2 to use ACR 3.1. Camera Raw 3.1 will include preliminary support for the Nikon D2x (something I am looking forward to) and Canon Rebel XT (something probably at least a few of you may be looking forward to).
Update 1/10/2009: Over the years, Adobe has changed things a bit. Recent versions of Adobe Camera Raw default to saving settings in sidecar XMP files. Both this and the internal Camera Raw Database are still options.