Jeff writes, “I help a friend who is running a Mac with OS X and she needs to open and edit TIFF files. I can open them in the Mac’s preview software, but I haven’t found an application that would allow a file to be edited and saved back to the TIFF format. Would you be able to help? A free piece of software would be optimal, but we are willing to purchase one that works well if it has a reasonable price tag.”
The Photos app included with macOS supports editing and exporting TIFF files. For some reason the macOS Open With menu doesn’t make this obvious and recommends other applications instead. If you have the Photos app open, you can drag the TIFF file into the app and it will automatically be added to the photo library. When you are done with editing, simply export the file back out in TIFF format.
The Photos app is admittedly somewhat limited in its ability to edit files generally. If you need to do more complex editing, a more feature-rich app might be better suited to the task.
For anything beyond the basics you need a more full-featured editor. The most likely free option for editing TIFF images is the Mac OS X version of GIMP. It’s a powerful image editor, but takes some getting used to because the interface is clunky and complicated. Since GIMP was originally developed for Linux, you get all of the assumed geekiness of implementation in an app with as many features as the full version of Photoshop. If you’re willing to spend a few dollars, Photoshop Elements should do almost anything you’d need for basic image editing and provides a more consistent experience. With a slightly larger budget, Apple’s Aperture will also do the trick.
UPDATE: Skip points out an extremely useful app I completely forgot: “You missed an old stand-by with your answer to this question. The app in question in Lemke Soft’s “Graphics Converter.” The app is so popular that Apple included a full version on every PPC PowerMac and PowerBook. It’s a great app and saved me a couple of times, even opening files that were corrupted and wouldn’t open in Photoshop Elements.” For $30, it’s worth every penny.