Chris Rasmussen · Infrastructure Guy · Code Dabbler · Photographer · Traveller

Adobe Lightroom – Transferring DNG files to another computer

Posted by Chris on Dec 19th, 2009 in Design, Photography, Software | 0 comments

This post assumes you are shooting RAW and using Lightroom 2

Both iMac machines at my place are used with Adobe Lightroom for photographic processing. Today I needed to transfer some photos from one machine to the other but Lightroom wouldn’t transfer the develop settings, only the files themselves. Here’s how to transfer the develop settings too.

By default Adobe Lightroom is configured to only store photo development information in the Lightroom catalog. This is fine if you only ever plan to develop photos using Lightroom using a single computer. However, if you want to transfer photos to another computer *and* keep the develop settings you’ve applied, the file will be transferred without the develop information. There are a couple of ways of getting around – here are the main ones.

Transfer the original file to the other computer with a sidecar XMP file (XMP stands for eXtensible Media Platform). The XMP file is a companion file that can go with the original RAW file to retain develop changes.
Use the increasingly popular DNG file format (DNG stands for Digital NeGative) and ensure the develop info has been saved into the XMP space within that file.

The XMP sidecar method is simple. If you use Adobe Camera Raw (ACR) to modify your original RAW files (e.g. CR2 for Canon, NEF for Nikon) just make sure the XMP file with the same name as the original image is transferred with the original image. ACR will recognise this file and load it accordingly. The XMP file be automatically created as soon as you make a modification to the original image.

The second method is what I choose to use as it combines the original image and the XMP data into a single file.

If you want to use DNG files within Lightroom, something I think is good practice, you need to do a couple of things. Please note that I’m using Lightroom for Mac on OS X Snow Leopard – the dialog boxes will look slightly different if you’re using Windows.

When you import your images into Lightroom import them as DNG files immediately, as shown in the screenshot below. To bring up the import files dialog click the File menu and select the option that suits you, e.g. ‘Import Photos from Disk…’)

Convert your existing images to DNG after they’re in your Lightroom catalog. This can be a time consuming process, depending on the speed of your computer and/or the number of images already in your catalog. To do this select the images you want to convert and click the Library menu then the option labelled ‘Convert Photos to DNG’ (or ‘Convert Photo to DNG’ if you have only 1 selected). The import window looks like the image below (these are the settings I use – be aware of the option that says to delete originals after successful conversion).

Ok so that’s your catalog nicely full of DNG files. Where to next?

The next step is to ensure that the DNG files also contain the XMP develop data – this is NOT the default setting in Lightroom 2. To do this select the Lightroom menu on OS X and select Catalog Settings or press Option+Command+, (on Windows select Edit then select Catalog Settings or press Ctrl+Alt+,). The following dialog will appear (select the Metadata section if it’s not already selected).

As you can see the box labelled ‘Automatically write changes into XMP’ isn’t checked – this is the Lightroom default setting. This means that any changes you make to the DNG file will be saved into the Lightroom catalog *only*; the italic text directly below option confirms this for you. To change Lightroom so that it saves develop information into the XMP space within the DNG file, enable this option and close the catalog settings window (on Windows change the setting and click OK). From now on the DNG files you use will contain the original image and any develop changes you make.

Hang on, my existing files won’t contain the develop info, will they? What do I do?

Good question! The answer is no, they won’t contain the develop info yet – luckily the solution is easy. If you want to make it so that your existing images contain the XMP develop data (assuming they’re DNG) firstly make sure you’re in the Lightroom Library module (the first link in the 5 links near the top-right of the Lightroom main window). Then you simply need to select the images you want to modify, click the Metadata menu and choose ‘Save Metadata to Files’ (or ‘Save Metadata to File’ if you’ve only got 1 file selected). On OS X you can also press Command-S or Ctrl-S if you’re using Windows. This will write the changes you’ve made, if any, to the XMP space within the DNG file.

From now on the DNG files are fully portable! You can take them in their current form – the DNG files – and copy them to a new PC or send to someone else without fear that your develop changes won’t go with them.

Whoa, is this safe? Can this break anything?

My disclaimer for this post is that you should be doing regular backups of your important data. If you’re already doing regular backups you have nothing to worry about; in the unlikely event that something does go wrong, you can restore your files from backup (if you’re not backing up your data PLEASE start doing it now, for your own sake). The above steps are non-destructive and safe for your images – I use this option and have never had a single problem with any of my images.