That essentially means you have infinite undo for your filters. What's more, adjusting filter effects is easier in Acorn 4 than ever before: You can click and drag on the canvas to adjust filters and effects, instead of needing to adjust the sometimes arcane settings directly. For example, when applying a Depth of Field filter, you can click and drag specific points around the canvas to control where and how that affect is applied.
When you want to lock down filter effects, you can flatten them.
Acorn 4 also gains a new, fun shapes generator. You can insert random smatterings of circles, rectangles, or hexagons. Oddly, though, you access the shapes generator only from the Shapes menu, and the generator doesn't behave like a traditional generator filter with the nondestructive editing options those filters have.
Acorn 4 also gains some new options for adjusting your images' levels and curves. When adjusting levels, you can optionally see a live histogram for your image. That levels tool also gains a midtone (gamma) slider. The new curves tool offers serious tonal control over red, green, and blue levels in your image.
Pros will know precisely what to do with those tools. Those like me will muck about with them half-randomly, seeing when our images look better or worse. The tools should work for both sets of users.
Acorn 4 is on sale for $30 both at Flying Meat's website and the Mac App Store for all of May. After that, the app will return to its normal $50 price. A free trial is available, too.
Acorn is a very, very good image editor, and has become a part of my daily workflow for Macworld, along with my photo editor of choice when we're going to print some digital shots.
Acorn 4 makes marked improvements to the app's feature set and usability alike. The new filter options and layout are excellent additions. The app's permanent residence in my Dock is a testament to its powerful editing options and its impressive ease of use.
At a Glance
With its its powerful editing options and impressive ease of use, Acorn 4 is the image editor "for the rest of us" and deserves a home on your Mac's Dock.
Price when rated: $30 though May; $50 regular price
Non-destructive filters make effects painless
Delightfully simple UI
Not as many filter options as Photoshop
Sign up for CIO Asia eNewsletters.