Aperture managed vs referenced files

8 things you need to know about managed vs referenced files in Aperture

01 Versions and Masters (Originals)

This is an important Aperture concept because it explains how your original files are always preserved intact.

• Versions: These are Aperture’s representations of your photos, not the photos themselves. When you import pictures, Aperture creates a Version for each one in its library, and this is what you see and work with. It’s a ‘virtual copy’ of the picture, not the picture itself. When you use the Aperture editing tools, you’re editing the Aperture Version, not the original file. You can create any number of Versions of the same image within the Aperture library and edit each one differently – but these are virtual copies, not new files on your hard disk.

• Masters (Originals): These are your original photos. Aperture never makes any changes to your Masters. They can either be imported into the Aperture Library itself (‘Managed’) or kept in their original location (‘Referenced’). Either way, they’re never directly modified.

02 Where your files are stored

Aperture will either ‘Manage’ your images by importing them into its own internal library, or ‘Reference’ them in their existing location.

• Managed: Managed files are kind of foolproof because if you can see the file you know it’s there, and the very fact of having your library on your computer (or external hard disk) means that all its images are there too. The disadvantage is that your Aperture library may be so large as to be unmanageable. A collection of 50,000 photos could produce a 500Gb library, for example. This is because the library contains all your Masters and all the copies you create in applications like Photoshop, plus the thumbnails, previews and other data accumulated by the library itself. If you want to know how big a managed Aperture library would be, check the total size of your whole image archive and then add 10-15%.

• Referenced: Referenced files stay in their original location, which may even be on a separate drive. The advantage of this is that the library is separate to your Masters and small enough to store on an internal disk drive while your original images are on an external drive which you can plug in if you need to edit them (you can view and organise your photos without the Masters being present). The disadvantage is that if the original files are moved or renamed outside of Aperture, the library may not be able to find them again – you’ll have to re-establish the link manually.

Aperture managed vs referenced files

My ‘referenced’ Aperture library is 53GB, and my image archive itself is 478GB. If I used a ‘managed’ approach instead, all my images would be consolidated into the Aperture library, which would be the size of both combined, i.e. around 531Gb – far too large for my MacBook’s internal drive.

5 thoughts on “8 things you need to know about managed vs referenced files in Aperture

  1. Hi Rod:

    Thanks for an enjoyable site. Generally a very good article discussing managed vs. referenced files. Having taught Aperture, I know how conceptually difficult this topic can be for many users. I know I am being somewhat pedantic and that too much info can be a problem, but hear goes with a couple of comments/suggestions. I hope you are not offended.

    Aperture no longer uses the term “masters”, replacing it with the term “originals”. Use of the old term may confuse students.

    You state, “Referenced files stay in their original location, which may even be on a separate drive”. This is may confuse some users, because for most image file imports the original location is a card in a card reader. This is one of the most dangerous aspects of dealing with referenced files. In paragraph 03, you specifically recommend using the “In their current location” setting. I have personally had to tell many people they have lost their original files, because they inadvertently selected this setting, where the original location is a card. They see their images import into Aperture. They might even back up their hard drive first, because they are cautious, but in short order they reformat their card, in-camera, which was the “original” location. Oops! If you must use referenced files, I feel a better methodology is to always use the “Choose” setting, as it reinforces that you are copying the originals to a new location. I realize there may be times where the files already exist in their final resting place and the “In current location” setting is appropriate, but users must be extra vigilant to avoid mistakes when using this setting.

    In paragraph 07, the implication is this is the way you would use an external editor. Certainly you could do it this way and if you use multiple external editors, it is required, unless you want to change preference pains regularly, as Aperture currently supports only one external editor at a time. However, if you predominately use one external editor and/or plugins, you can set your preferences to use this external editor. Once this editor is set, it will appear as an editing option, in the Photos menu and in the control click/right click contextual menu. The advantage to this approach is that Aperture manages the export/import round trip. Less work and fewer opportunities for a mistake.

    I feel the topic reviewed in 08 should include discussion of a third choice, multiple managed libraries. This allows the user to address internal storage space issues without going the referenced route. There are many ways to manage this approach, e.g., a current year, plus portfolio level images library on your internal drive and an archive library on the external drive. Someone who manages a very large database of images might take a yearly library approach. A professional photographer might have a library for each customer/project. Like all approaches, there are pros and cons. I feel the biggest pro to this approach is the reduction in human error possibilities managing referenced image import and the created files in the finder. I feel the biggest con is that Aperture can only search within the open library, so a multiple library user needs to have a good system for defining libraries, or they will struggle to determine in which library an image resides.

    I hope this commentary is useful. Thanks again for a useful site.



    1. Thanks for those comprehensive observations, Scott. I think the one about not referencing file on a memory card is a particularly good one, and I wish I’d though of that!

      I also take the point about the swap from ‘masters’ to ‘originals’. I’ve been using Aperture a long time, but I hadn’t noticed that.

      I’ll update the post with those points in mind.

      Point 7 is not about using external editors and I can’t honestly see where I implied it. It’s about situations where you might want to extract a file from a managed Aperture library for use externally, for whatever reason – I think the DxO conversions I mentioned are a particularly good example. Aperture is not always the best RAW converter, and you have to resort to means like these to use another, or to send your originals to other people, for example.

      I think it would be better to cover external editors in a separate post.

      I have tried multiple managed libraries, but they don’t work at all well for me. Others may feel differently, though, so thanks for the suggestion.

  2. Thanks for the kind comments back my way Rod! I apologize for misinterpreting Point 7. I took it to be inclusive of all external editing, not specifically for RAW and/or batch processing. I have not found the need to do this type of work personally. You and your readers, who use Aperture and have this need, may want to explore the Catapult plugin. It is an Aperture plugin that facilitates round-tripping RAW files to DxO Optics Pro, ACR and Nikon Capture. It does not cover every base, but may be helpful to some. Below is a link to their site and a review:





  3. Hi Rod,

    I really enjoyed reading your thoughts on referenced vs. managed libraries. I’ve been spending entirely too much time deciding which approach to use as I move all my images from PC to Mac. I’m a bit of a control freak when it comes to the handling of my files, so the managed approach goes against my nature. However, I’m just a JPEG-only rank amateur snapper, so I’ve decided to use iPhoto in managed mode for it’s sheer convenience. FYI, iPhoto can import photos with a managed, referenced or combo approach. Also, iPhoto can open an Aperture library, and vice versa, so I may graduate to Aperture at a later date.

    I’ve also decided to do a couple things to my images before importing them into iPhoto. I use the Automator to give them a more descriptive filename with the image date and time, and I use Picasa to add geotags and keywords. That way, my iPhoto masters will have that info in them should I ever decide to break out of the Apple camp.

    Steve makes excellent points about the danger of using a referenced library unless you are really clear on where your images will reside. Another thing for folks using an external referenced library: If you back up your Mac with an app like Time Machine, your external drive holding your photos must be connected during the backup if you want your photos backed up, too.

    Thanks again for your excellent and timely article!

    Rod T.

  4. Very informative Rod, and also Scott, your comments were very helpful. Being in a position of starting from scratch with Aperture and a Macbook Pro (moved from Windows), I was looking for “best practice” suggestions.

    Scott B.

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