Before I start this article, let’s set the record straight. I’m a long time Aperture user… I started with Aperture the first day it was released. My Aperture library tracks my evolution with digital photography and it was one of my favorite tools for years.

A while back I decided to switch from Aperture to Lightroom. I’ve always used Photoshop in conjunction with Aperture for my Panoramic work and advanced retouching.

Recently, Ive been absolutely inundated with people asking me how to move their libraries from Aperture into Lightroom. I get these questions as I taught many people a lot about Aperture as one of the authors of the official Apple Pro Training Series on Aperture. In fact I even produced a lynda.com class on the topic.

DISCLAIMER: This article isn’t about why you should move or if you should wait. Its merely about HOW to move your stuff.

How to Move Files from Aperture to Lightroom

In this example I am moving my largest Aperture library. The steps aren’t hard, but with a large library they can take some time. My advice is don’t rush and make sure you backup both your Aperture library and Lightroom catalog before you start.

Things to Do First in Aperture

Before you move several thousand files over into Lightroom, its a good idea to do a little housekeeping. Ideally the move you make will be a one time move, so getting things right is important up front.

Check For Any Offline Files

I tend to use a Referenced Library in Aperture (one where all the images were on a drive or drives instead of just pulled into the Aperture Library). This was easier for me to organize and backup. In any case though the same advice holds true for managed libraries. Get everything in sync up front.

1. Launch Aperture and select the Library tab.
   
2. From Your Library choose Photos to see all your photos in the whole library.
3. Click the Filter button near the search field to filter your view.
4. In the Filter dialog choose Add Rule and select File Status.
   
5. Check the box next to File Status and set it to Offline to see all files that seem to be missing or were moved and need to be relocated.

Reconnect Offline Files

Knowing that files are offline is only half the battle. You now need to connect those files back so they can be referenced and moved. Select the images that show offline in the Browser.

1. Select all images which show as Offline. This should be all images shown if you use the Filtered view we set up previously.
2. Choose File > Locate Referenced File.
3. In the new dialog box, examine images and their previous path. You can also note the fie name for missing files and search at the Finder level manually if you have problems.
4. Select the drive and base folder where you think the files live. Aperture will search to find the missing files.
5. When a matching thumbnail is shown, click the Reconnect All button to reconnect all files that existed in the former directory to reconnect them
6. Continue until all of the remaining files are reconnected. You may need to search multiple drives if youve spread them out over many hard drives. Mine are all on one Drobo 5D so theyre easy to find (and backed up to a second Drobo and to the Cloud).
7. When all files are connected Click Done.

Get Big Previews

Aperture and Lightroom process images differently not a surprise except its important to note that the bulk of your Raw adjustments will be lost. But Lightroom can import the Aperture previews for reference or printing if you create them first.

1. In Aperture choose Aperture > Preferences.
2. Choose the Previews tab
3. Set Photo Preview to Don’t Limit for Full Size previews. You can also chose Half Size if space is a concern.
4. Set the Photo Preview quality slider to High ( value of 1012).
5. Close the Preferences dialog.
6. Hold down the Option key and choose Photos > Generate Preview to make fresh Preview files.
7. A status bar appears as the process is loaded indicating Scheduling previews for rendering. When it completes it will disappear.
8. At the Bottom of the Screen Click the Activity Monitor icon (a spinning gear) to track progress. You can also choose Window > Show Activity to see progress.
9. When the Previews complete you can close the Activity Monitor. This process can take some time for a large library.

Confirm Which Library You are Moving

Its quite possible that you have more than one Aperture library on your system. Make sure you know its exact location on your drive.

1. Choose File > Switch to Library > Other/New
2. Click on the Date Modified column to sort from Newest to Oldest.
3. Take note of the library at the top. It should also have the phrase (current default) next to its name.
4. At the bottom of the dialog, not the full file path. Write this down for good measure.
5. Close this dialog without choosing a new library using the close button in the upper left corner of the window.

Make the Move to Lightroom

In order to move your Aperture (or iPhoto) library into Lightroom, you’ll need to have Lightroom 5.7 or later installed. To check which version you have choose Lightroom > About Adobe Photoshop Lightroom (Mac) or File > About Adobe Photoshop Lightroom (Windows).

What Imports and What Doesnt

Before we bring files in, lets review what will translate into Lightroom. This is an important limitation to review.

The following items should import correctly:

• Flags
• Star Ratings
• Keywords
• GPS Data
• Metadata that can be entered in the Info panel in Aperture
• Aperture project/folder/album hierarchy will be mapped as closely as possible into Lightroom collection sets and collections
• Import Full size previews from Aperture/iPhoto provided that they are up-to-date
• Aperture Versions will translate into Virtual Copies in Lightroom (without adjustments)

The following items should import but are remapped to keywords:

• Faces (face naming tags are mapped to keywords)
• Rejects (files designated as Rejects in Aperture will be imported into Collections > From Aperture > Photos Rejected in Aperture)
• Color Labels (Color Labels are mapped to keywords: Red, Orange, etc, including support for custom label names)
• Stacking ( Stacks information is mapped to keywords: Aperture Stack 1, Aperture Stack 2, etc)

The following information is ignored and cannot be imported into Lightroom:

• Image adjustments
• Smart Albums
• Face Tag Region of Interest (face naming tags are mapped to keywords)
• Any kind of creation (books, web galleries, etc) other than the collections that correspond to them

Start the Importer

To import your Aperture library into Lightroom, you’ll use a pre-installed plugin. If you skipped the steps on preparing your Aperture library, you must go back to the start of this article and read those first (otherwise beware of possible errors).

1. Choose File > Plug-in Extras > Import from Aperture Library.
2. A new dialog opens and Lightroom scans for existing Aperture libraries.
   
3. When the scanning is complete click the first Select button.
4. Navigate to the Aperture library you want to import. You earlier learned how to check which Aperture library was the current one in use so navigate to that file and choose it.
5. Click the second select button to choose a folder where to store the copied images.
6. Verify the number of files to be copied and the disk space needed.
   
7. If you don’t have enough disk space consider switching to a multi-drive solution like Drobo.

Set Your Options

Before you import, there are important options to choose. These options will better control what is imported into Lightroom.

1. Choose File > Plug-in Extras > Import from Aperture Library.
2. Check the first box to import full sized previews into Aperture. Full size means use the full is made by Aperture so be sure to check the previews or rebuild them in Aperture first as we previously discussed.
3. Leave the second box checked so only keywords that have been applied are imported.
4. The middle section lets you convert color labels and stacks into keywords. I recommend using both of these options.
5. The last two options are important. They deal with referenced Aperture libraries.

• If you want to leave files that are referenced by Aperture in their same location, check this box. This will leave all referenced files in their current place and simply add them to Lightroom.
• If you want to duplicate and copy referenced files so a new copy is made, uncheck this box. This will make sure that Aperture has its copy and Lightroom works with a different copy.
• All managed files will be copied automatically using the location you set earlier.
• I recommend checking to place imported Previews with the originals so Autostacking works best in Lightroom and files stay organized

6. When done, Click OK to store the options.

Start the Import

I strongly recommend verifying that you have enough disk space to hold the copied files. Its also a great idea to backup both your Aperture library and Lightroom catalog if you want to be bulletproof against errors. If youre running this on a laptop, be sure to plug the computer in so you don’t have a dead battery part way through.

Once youre ready to import, you can click the Import button to start the process.

Once you click the Import button, Lightroom starts to process your files. Theyll be added into a Collection named From Aperture. When the import is finished, you may want to clean this folder up by rearranging things a bit. It should be a close match to your Aperture structure.

Conclusion

I found the process of moving my Aperture library over to be easy albeit a bit time consuming. The extra processing and time was on the Aperture side to ensure that all files were online and that I had full-sized previews for adjusted images.

Once I invoked the import, the process was pretty straight-forward and took only about as long as importing the same number of images from a hard drive or memory card. Id personally transitioned from Aperture almost completely about a year ago. Having the ability to bring over my complete library was the final step to making sure no good images were left behind.

For those of you on the fence waiting for the new Apple Photos app, just file this information away for the future. If youre happy in Aperture stay. If you like the new app when its released, use it. For me, Im quite happy for the move as I see a substantial jump in quality due to the way that Adobe processes its Raw files.