Organizing Your Edits

While using Open with External Editor is fairly straightforward, the fact that Aperture must first create a master image to send to an external application means that you will want to be thoughtful about where you perform your edits: in Aperture or in your external editor, or in some combination of both.

Applying Edits in Aperture to an Image You've Already Edited Externally

Suppose you want to apply some very selective edits to an image. Aperture doesn't provide masking tools, so you use the Open with External Editor command to send the image to Adobe Photoshop. As you saw in the previous section, Aperture renders a new master and then opens that new document in Photoshop.

In Photoshop, you make your changes and then save the image. When you return to Aperture, the new image that Aperture created shows your changes. Next you apply a Color Monochrome adjustment in Aperture. As always, Aperture makes no changes to your original file; it simply adds the adjustment to its list of edits for that version.

This is a perfectly legitimate edit, but now consider this: You notice that the image needs a little touch-upsomething that you didn't see beforethat can be performed only with Photoshop's Dodge and Burn tools. So you choose Open with External Editor again.

Because your image has an Aperture edit applied to itthe Color Monochrome adjustmentAperture must now make another master image. This time, it takes the file that you edited in Photoshop, applies the Color Monochrome adjustment, and then writes a new file, which it sends to Photoshop. You now have three master images, each of which has different edits, and each of which is at least as big as your original file.

One of Aperture's strengths is its ability to create new versions by simply writing a small text file. By spawning all of these new masters, you've lost some of that advantage.

Re-Editing an Image You've Already Edited Externally

If you edit an image in an external editor, save it, and return to Aperture and then decide that you want to perform more edits on that image using your external editor, you can again choose Open with External Editor.

However, because you have not applied any Aperture adjustments, Aperture does not need to create another master image. It can simply send the same file back to Photoshop.

Using Photoshop Layers

If you create additional layers in Photoshop, when you come back to Aperture, you'll see a flattened view of your image. Since Aperture doesn't have any layering capabilities, it can't display individual layers. However, all of your layers are fully preserved in your master image. If you send that image back to Photoshop, you will see all of its layers, as long as you didn't first apply any Aperture adjustments. If you've applied adjustments, then Aperture will have to flatten the image when it builds the new master file that it sends back to Photoshop.

Tip

If you're using Mac OS X 10.4.6, be aware that a bug in the operating system causes Photoshop documents to be displayed incorrectly if they contain an alpha channel. If your images appear in Aperture inversed or with odd contrast, try opening the offending images in Photoshop and deleting any alpha channels. (Obviously, if you want to preserve the channels, you should save a copy of the images first.)

Tip

If you're using Aperture 1.0 or 1.0.1, Photoshop documents will always be flattened when you send them on the Photoshop round-trip. The upgrade to Aperture 1.1 is free, so there's really no reason not to upgrade to the newer version.

Strategies for Working with External Editors

With the preceding scenarios in mind, it's possible to derive some broad guidelines for working with an external editor.

• Ideally, you want to make only one trip to an external editor, so that you create only one new master image. Therefore, you should try to perform all of the edits that you need the first time you go to your external editor. In general, it's best to get your external editor tasks out of the way as early as possible. You usually need to go to an external editor only to use touch-up or compositing features that aren't available in Aperture. You want these types of edits out of the way before you start any tone, contrast, or color correction.

• If you want to ensure the greatest editing flexibility in your files, use your external editor only for those edits that can't be performed in Aperture.

• In your external editor, try to work using techniques that can be easily edited or redone. In Photoshop, work with layers, adjustment layers, and other effects that can be altered or removed. You can return to these edits later and adjust them if you need to.

There's nothing really wrong with executing repeated round-trips on an image. It's just not the most efficient use of disk space, and it creates more images in your project, which can sometimes be confusing.

When deleting, to help you keep track of which images are master images, be sure to select the Show Warning When Deleting Masters option in the Aperture Preferences dialog box. With this preference enabled, Aperture will warn you before it permanently removes a master image.

Moving Images Out of Aperture

Finally, you can simply export your images to the Finder. If you later want to edit them in Aperture, you'll have to reimport them. We'll discuss image exporting in the next chapter.