When we reviewed Pixelmator 1.6.2 eight months ago, many readers were quick to demand a review of their favorite Mac OS X image editor: Acorn. We decided to hold out for the next major release—so here we are with a look at Acorn 3.1.2 for the Mac.
One of the first things you notice about Acorn is its tiny footprint. It's listed as 14.6MB on the Mac App Store, but it's actually 31.9MB on the disk, which is still amazingly small for a program with this robust a feature set. People with smallish laptop SSDs are always looking for ways to save space, so compact apps are a plus.
The Interface
Acorn's interface is similarly minimal and tastefully executed. It's not brimming with animated transitions and its overall gray look means it's good at staying out of your face to let you focus on your images. Almost all of the application's interface is concentrated in one large palette, which hosts the tools, contextual tool options, and the active document's layers.
When I first saw the interface a couple years ago, it reminded me of The GIMP—never a good thing—but after using it for a while, it was clear that the interface is far tidier and compact than the open source image editor.
Small things add up to give Acorn a really pleasant workspace. With the exception of the layer style/FX popup, palettes are non-modal, so you have lots of room to customize a workspace and keep clutter to a minimum. You can use option-scrollwheel for zooming and, for those coming from Photoshop, you'll be comfortable with a lot of the Acorn key shortcuts and modifiers:
- control-option mouse click interactively resizes the brush
- holding the command key toggles the Move tool
- shift constrains strokes to 90° angles
- tab hides/shows the palettes
- command -/= zooms out/in
- X to flip foreground and background colors
There are more key shortcut and workflow similarities to Photoshop, like guides being created by dragging off of the rulers and other things, but you get the idea. Acorn doesn't pretend to be as powerful as Photoshop, and developer Gus Mueller hasn't reinvented the wheel where there's no need to do so. The only Photoshop-style shortcut I find missing is command-spacebar-click for zoom, since command-= requires taking your hand off the mouse and a tablet pen doesn't have a scroll wheel and this is a pretty common standard for zooming in image editors.
Acorn also has an image thumbnail browser, but it's pretty bare bones:
The only customizable thing is the thumbnail size.
Coming from Adobe Bridge or even from GraphicConverter, this is quite limited. It offers no sorting controls, image info, or contextual options. I don't mind "minimal," but I feel like Acorn really needs QuickLook support at the very least, since you have to open images or increase thumbnail size to see a larger shot of the contents.
The Tools
The tools in Acorn are better fleshed out. Most of the basics of a modern image editor are there: 64-bit code, multiple undos, pen tablet pressure support, good gradient controls, layers with masks, quickmask, clone, dodge, burn, smudge, live cropping, color profile support, Boolean selections and feathering, gradients, and text tools. And of course, the staple of all image editors...
Brushes
Acorn comes pre-loaded with a lot of pen tips and paintable image stamps. In the dropdown menu next to the brush tip preview, presets include textured pencils, felt-tipped angled pens, watercolor, and some cheeky effects like planet stamps. "Precision mode" slows the cursor down to give sub-pixel precision to some very broad movements; using a mouse can get you very accurate strokes.
The basic brushes feel very nice and the Brush Designer gives you a lot of customization of the brush controls.
Of the tablet support features, only pressure sensitivity is supported, so angle-based brushes are static. Acorn's not really meant to emulate real-world media, like Painter or ArtRage try to do, and the few media brushes are just image stamps with Brush Designer setting tweaks. So you won't be getting watercolor wet-on-wet effects like a proper paint program—the results aren't convincing.
At first, it looked like the Acorn brushes maxed out at 100 pixels, but Acorn can actually go up to any size when using the control-option modifier or command-]. I don't expect a lot of depth from a basic image editor's brushes but one complaint I have about Acorn brushes is that the falloff of the softest edge is still hard at the edge:
Compared to Photoshop's 100 percent soft brush, Acorn drops off the edge too quickly:
I don't hold up Photoshop's brush as the standard but clearly it is harder to make a soft stroke in Acorn.
Other than that, brushes in Acorn will be fine for most needs.
Layer Support
Another staple of modern image editing is layers, and Acorn's layer support is decent enough. Layers can be masked, grouped, and you can command-click to load layer transparency as a selection. You can unlink the mask transformation from the color to do things like move text around while keeping a background mask in place. There are tons of alignment and translation controls.
Acorn's true power is that it supports vector shape layers and has editable Bézier curves, features rarely seen together in budget image editors. You can make rectangles or circles, but the Bézier pen tool lets you work with vector curves. Combined with the live layer styles and presets, you can get some fun effects and make some templates, with effects in the stack being toggled and reordered however you want:
That type is still editable even though it's filtered.
Filters
The Acorn filter set, much like that in Pixelmator, comes from Apple's CoreImage filter set and isn't professional grade, but Acorn has one-upped the Pixelmator implementation by providing customizable presets for many filters via their custom interface:
Acorn does this for many sets that, like Comic Effect, don't have any customizable options, but then I realized the presets store multiple stacked effects, so you can do things like make a slightly-blurred, hue-shifted CMYK halftone for a "photo of an old magazine cover" effect. For a budget editor, Acorn's vector tools and wealth of preset options really make it a little workhorse capable of doing some serious non-destructive editing.
Layered Screenshots
One of the cooler features of Acorn is the ability to take screenshots that put all your windows with drop shadows into a layered document, with every active process that draws to the screen clearly marked in the layer names:
I was worried that you'd always have to have Acorn in the screenshot—but hide the app and you can show anything that was behind one of its windows. Some shareware that does, this but it's the first time I've seen this handy tool in an image editor. It's great for authors or bloggers who do tutorials.
Robust Text Controls
One of my main complaints about any app that relies on Apple's type frameworks is that they lack the controls needed to set finished-looking type. Even if you want to make a simple Web banner, you need control over kerning and leading, so it's important that Acorn offers both kerning and leading controls:
The ampersand pops open the OS X OpenType controls for fonts that support those features
It's a professional set of tools, but unfortunately there are some wonky behaviors I couldn't get around when trying to make large multi-line text in a box:
The blip you see at the top is a descender from a g.
I had to add two hard returns before that to bring it down, but when I exit the text tool, it snaps back up. Also, since the max line height is 100, it's not possible to make large multi-line copy look right. That number needs to at least go up to 1000. Once the kinks are worked out, the Acorn type tools are easily the best for an image editor in this price range.
Instant Alpha
Since the target audience for a budget image editor is casual users, these apps should have some way of cutting people out of pictures. "Instant Alpha" is Acorn's tool for this. It's a simple workflow: click on the background color you want to erase and drag to the right to expand the threshold of colors that are made transparent. It's basically the Magic Wand selection with a nuclear option. My first test was pretty easy:
In one drag, I was able to knock out almost all of the background:
With a few more selections, I was able to get rid of the rest. Testing it with a background gradient showed the edge was clean, if a little aliased:
Predictably, a more complex test with hair was less successful—but you can't blame one guy for not getting this right, since Adobe only recent matched the quality achieved with professional extraction plug-ins in Photoshop. (If you want better cutouts, I recommend Fluid Mask—it's a standalone app and they fixed their maddening licensing problems so it's worth the cost if you don't own Photoshop.)
That said, I do have one request for Acorn's Instant Alpha: an option to put the transparency into a mask, since people may want to make a trade-off by going too far with the tool and then painting back in opacity.
PSD import and export
Acorn supports opening and exporting Photoshop PSD images. I tested some images saved from Photoshop CS5, and they all opened with layers intact. Where adjustment layers were used in Photoshop, Acorn just made an empty layer, which is a fine approach. But in cases where it's important to preserve the appearance of an image (as with adjustment layers), it would be nice if you were given the option to open the flat PSD composite that is saved in Photoshop documents. This is how Preview opens them and, with my swamp thing adjustment layer below, it's the most correct rendering of what you see in Photoshop, even if there are no layers intact:
It's a minor issue, though, and many other apps handle PSDs the same way.
Lion-specific features
New to Acorn 3 are options specific to Lion users. First is fullscreen mode, which creates a Mission Control space when you hit the F key. Each newly opened document from within a fullscreen space creates another space and the Acorn palette floats atop each one when you switch between them. Depending on how you use spaces, that might be too space-heavy for you or just right. The only downside to this in my experience is that closing fullscreen documents can be slow-ish because the OS has to close the entire space with an animation.
The other Lion-specific features are support for versions and autosave, Apple's versioning system that is like a per-save version of Time Machine for documents. It's a great feature for certain things but is off by default in Acorn, due to feedback from Acorn's existing users. I'll explain what those complaints might have been, but first I'll cover the basics of how this operates.
The default behavior should be familiar: the File menu shows two options for saving (Save and Save As...):
When you enable versioning and autosave, the menu shows two different options (Save a Version and Duplicate):
When you save a version, changes are written to the file and retained in the document's history. If you decide to go back, you can select the document title bar and pick Browse All Versions... and a Time Machine-like interface comes up so that you can browse each save:
Simple enough, and it's a pretty great system if you want access to all that history data. But this system comes with some significant trade-offs.
The first problem is that, in order to have changes written to a different document, you have to pick Duplicate and then close the other window, then save the new one instead of using the simpler Save As operation. Versions are great for reverting old screwed-up files, but when dealing with creative apps, versions are usually made when you reach some milestone in a document's development (hair finished retouching, text set properly, etc.) That might also branch to provide different options if you feel like you want to bang out different approaches for mockups so, with no way of tagging milestones or branching versions like a virtual machine's snapshots, you are left browsing a linear chronological list of unfamiliar times (7:35 version!). Versions and autosaves, being designed solely with one überdocument in mind, don't fork in creative ways.
The second problem is that this approach balloons the file size since nothing is thrown away. My cropped Brahms 3D sculpture image saved as a versioned document is 15.7MB, while the non-versioned one is 3.9MB. These trade-offs would seem to make versions more sensible for text and coding (I'm still dying for this to be added to BBEdit) but less sensible for images and creative work.
So versions are off by default in Acorn. Kudos to the developer for not trying to oversell this as a feature by leaving it on. Too many companies add something and, even after beta users complain, leave it in or even make it the default because marketing needs bullet points to sell, and anything less than “on by default” means it's not the hottest thing ever that you need to buy NOW.
Scriptable
Acorn is scriptable and automatable via AppleScript, Automator, and JavaScript. For basic file operations, even Python and shell scripts are supported.
As someone who was late to the scripting and coding party, my scripting knowledge is limited to bash and C-ish languages, so I was pleased to see that you can also use a shell script to have Acorn send images to other apps. This simple script successfully sends the foreground image to Fluid Mask:
For more sophisticated scripting of image operations, Acorn has AppleScript support and its functions can be found in the .sdef file in the Acorn bundle:
It's another example of how Acorn is made to be a sleek little workhorse.
Acorn Compared to the Competition
Acorn has some stiff competition in the $100-and-under range, and each program has its own distinct advantages and disadvantages. Here's a quick rundown.
Pixelmator 1.6.2
Pixelmator surprised me with its power when I reviewed it. It was clear that the developers, in contrast to Acorn's, were really trying to nail as many of the Photoshop features as possible. It's not a complete replacement for Adobe's app (nothing is) but it comes closer in that regard than Acorn, if this is what you're looking for.
Pixelmator benefits:- Better Web features. Live preview of the document with optimized slices give Pixelmator a big upper hand for Web design. Acorn's Web features are limited to a single optimized image preview (no slices) and there is no control for GIF palette limit.
- Better layer handling. Clipping layers, lockable transparency, linkable movement between layers, merging of layers, basically everything you can do with a Photoshop RGB layer
- Curves. I wouldn't have a problem with Acorn lacking curves if it used a gamma-based brightness/contrast adjustment. The one it has is an old-school “flood with white/black for brightness and toss away smooth gradations for contrast,” so it's butchering images compared to a curve adjustment. The levels control in Acorn doesn't have a mid-point slider, so it's really just a histogram with clamp controls
- Better cloning tool. Acorn's is limited to a 100 percent hard edge, which is almost never what you want to retouch an image. Sample all layers in Clone tool is a pretty big advantage if you do touchups to images
- More advanced color adjustments: Selective Color Replacement and Channel Mixer
- Area averaging for eyedropper
I feel like Acorn's interface is a little clearer for image editing novices than Pixelmator, and it has a few features that aren't matched by Pixelmator:
- Bézier tool and vector layer support
- Live layer styles
- Better type handling
- Has a smudge tool, which is important for editing layer masks
Pixelmator is a beefy app and the just-released Pixelmator 2 looks like it will close the gaps on the Acorn benefits and even add some more Photoshop goodies like content-aware fill. It doesn't seem to have live styles, though, and that's a big Acorn advantage.
Acorn vs. Photoshop Elements 10
Adobe is very selective about where it puts its high-end tech in PSE and I feel like Acorn and Pixelmator are making it look stingy. Still, it has a lot that Acorn doesn't have for image editing:
Photoshop Elements benefits:- Better printing options with Adobe's rendering intent and profile conversion settings
- Grayscale and 16-bit document support. You can convert to 16-bit but if you're opening a 16-bit document, it will keep the color and edit/save to 16-bit
- Much better cutout tools
- Red-eye filter
- Healing tools (like a magic clone tool for dummies)
- Brightness and contrast adjustment is gamma-based for better quality and also has a somewhat limited curve tool:
- Various adjustments that appeal to consumer photographers
- Area averaging for eyedropper
- Recompose tool. Made Sophie's choice a little easier by letting her remove child from photos after war
- Realistic media painting tools and filters
- Photoshop filter support (32-bit only)
- Better type handling (for shame, Adobe)
- Better color profile handling. PSE only lets you convert to and from sRGB and AdobeRGB.
- Vector tools aren't just cheesy shape presets
- Half the price of PSE
- 64-bit
Photoshop Elements is more strictly a consumer-oriented photo editor and for that it's definitely better than Acorn. The tools and adjustments, although limited compared to Photoshop, produce higher quality results. But Acorn's advantages are pretty significant and you couldn't use PSE to combine vector and raster images, unless you like heart shapes on everything.
Acorn vs. GIMP
The image editor that's hard to love has many followers. In a pinch, it can serve you well, but it's just not well-integrated into OS X due to its reliance on X11. Still, it's an image-editing heavyweight and is the most full-featured app covered here. There are just too many image editing tools The GIMP has that Acorn doesn't have to list here.
GIMP benefits:- More professional image editing tools all around
- $0 price tag makes it recession-proof
- If you need to rewrite the application, go nuts
- Doesn't feel like it's running on an Irix machine, circa 1992
- Far better type handling
- Vector layers and live styles (GIMP only has paths)
The GIMP would be a lot easier to recommend if it had a native OS X open/save dialog. Omissions like this just make using it a drag and slow it down considerably.
What none of these apps gets you: CMYK support
For some people, CMYK support is the elephant in the room when you're talking about image editors. None of the applications mentioned above support CMYK, and my feeling is that coding time is best spent elsewhere, since CMYK support is less relevant than it was in the past. I am a magazine art director and my entire workflow is RGB-based, with CMYK conversion being done at PDF-creation time by Indesign. I ask photographers to give me RGB images since I know more about my press inks and paper than they do. Even when I print on my Epson R1900 and 7890, I use RGB documents and Photoshop handles the conversion to the printer's ICC profile. People mistakenly think that because their inkjets use CMYK (as well as a bunch of other) colors, that this means it's more accurate to send CMYK documents. It's actually way worse, since printer software can interpret and translate sRGB or AdobeRGB color spaces, but when you're sending completely different CMYK color to a printer that's likely using between six to nine inks, worse translation takes place unless you use professional ($$$) RIP software.
As I explained in my GIMP 2.6 review, CMYK support is tricky because of factors like ink dot gain, local CMYK standards, and hardware calibration (your eyes would bleed from squinting if you saw how dark and murky a press-calibrated screen is). The rare CMYK work I do is for strict value tweaking with custom CMYK gain curves, where I'm referencing a Pantone booklet and I have a press proof for matching, since sending a CMYK file alone isn't a guarantee the press operator won't screw it up. These are highly advanced techniques that are beyond the scope of both casual users and a $50 photo editor, so CMYK in consumer hands is more of a liability than a feature. I hope this helps get more “Where is CMYK?” forum posts off of budget image editor support forums.
Conclusion
It's hard to run through an image editor like this and give it credit where it's due since I have to explain a lot of what's missing and can't spend too much time fawning over the program's greatness. That skews the review to sound almost negative, but I like Acorn and I get it. It's not a Photoshop clone, it's not dumbed down, it has vector tools, good (if buggy) type handling, and it's laid out in an uncluttered way that means a lot to those for whom this program is intended. Nice touches make this an easy app to recommend for image editing on the cheap, but what it lacks, even within this context, makes it just shy of great. I don't see greatness being too far off, but the competition isn't standing still, either.
Pros- Easy learning curve for novices
- Very good text handling (once kinks are worked out)
- Bézier curves and vector layers in an image editor
- Live layer styles are non-destructive
- Scriptable
- No red eye tool
- Clone tool is only hard-edged
- Bad contrast and brightness tools
- Limited Web export features
- Some bugs and stability issues seen during review
- A small app with a big heart and lots of potential
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