Defining An External Editor

There's nothing particularly magical about Aperture's round-trip capability. It simply launches the application that you've specified as your external editor and then passes that application a particular image. Nevertheless, the feature is very handy, and you'll quickly find yourself integrating it into your Aperture work.

Before you can open an image in an external editor, you must specify what you want to use as that editor.

Here's how to define an external editor:

1.	Choose Aperture > Preferences to open the Preferences dialog box.
2.	In the Output preferences, click the Choose button beneath the External Image Editor field (Figure 7.1). Figure 7.1. In the Aperture Preferences dialog box, you can choose a program that you want Aperture to launch as an external editor as well as specify how Aperture should pass files to that program.
3.	In the resulting dialog box, navigate to the image editor of your choice. For the rest of this chapter, we'll be assuming that you're using Adobe Photoshop, but you can specify any editing application.
4.	Set the External Editor File Format pop-up menu to the format that you want Aperture to use when it passes your files to the external editor. If you ultimately need to produce TIFF files, than sending your images in TIFF format may be the most convenient option. However, if you're using Photoshop as your external editor and you intend to create layered files or use other features that are supported only by the Photoshop file format, then select PSD.
5.	Close the Preferences dialog box.

To ensure that you have properly configured your external editor, perform a quick test. Select an image and choose Images > Open with External Editor or press Command-Shift-O. The image you selected should open in the program you specified as your external editor. If it doesn't, check your preferences to confirm that they're configured properly.