A simple yet powerful feature that often goes unnoticed in iPhoto for OS X is side-by-side editing mode, enabling the user to view and edit two or more photos in real time while still being able to directly compare images side-by-side.
To get started, open iPhoto on your Mac and navigate to the photos you wish to compare and edit. Select at least two photos by holding the Shift key and selecting sequential images or holding the Command key and selecting non-sequential images. Your selected images will be highlighted in yellow.
Select the two or more images in iPhoto. Your selections will be highlighted in yellow.
Next, press the Edit button on the bottom right of the iPhoto window. This will launch iPhoto’s familiar Edit screen, but instead of displaying a single photo, both photos you chose earlier will be displayed side-by-side.
The photos you chose in your iPhoto library will be displayed side-by-side in the viewer. The active image will be highlighted in white.
One of the photos will have a white outline. This is the “active” photo and any adjustments you make using the controls on the right of the window will apply to the outlined photo only. Click the other photo to make it active and apply your adjustments and edits.
If you change your mind and want to compare a different photo, simply select the photo you want to replace, highlighting it in white, and then use the image browser at the bottom of the screen to select another image from the same library or album. You can also change the selected image by pressing the arrow keys on the top right of the viewing window.
Use the image browser at the bottom of the screen or the arrows at the top to change one of the compared photos. If you wish to remove a photo entirely, click the “X” in the upper left of the active photo.
If you want to return to editing just a single photo, highlight the photo you want to remove and click the “X” in the upper left.
While you’ll most often want to compare just two photos side-by-side, selecting more than two photos will also work. Simply select the number of photos you want to compare and iPhoto will arrange them to fit the available viewing space.
Compare as many photos as you wish using this method.
Side-by-side editing is a valuable tool that lets both amateur and professional photographers quickly compare and modify similar photos. Be sure to add this simple tool to your iPhoto workflow.