One Step Effects and additional edits
One of the difficulties of editing video is that it's time consuming. Apple has attempted to make common edits easier by introducing One Step Effects. To make a clip fade to black and white, for example, you select a portion of the clip and choose Clip -> Fade to -> Black and White. To do that manually you would make the selection, split the clip, open the Clip inspector, apply the Black and White video effect, close the inspector and add a Cross Dissolve transition.
These effects are cool and helpful, but here's the best part: Since the building blocks of each effect are features that already exist in iMovie (you could do them yourself), the edits are left in place to tweak later, if you choose. And if you don't like the effect, choosing Undo once restores the clip to its pre-effect state.
iMovie '11 has a few new editing capabilities. For example, it's now possible to add footage shot against a blue background and choose Blue Screen to knock out the background. Previously, Green Screen was the only option, which made green items disappear. A new Side by Side effect is similar to the Picture-in-Picture option, letting two clips share the screen vertically. The clips are cropped automatically, but with some clever adjustment with the Crop tool you can gain some control over what appears in each side.
This version also includes a Transition Overlap control, something that existed in iMovie '09, but as an option that appeared only when you added or removed transitions for an entire project. The setting controls how two clips overlap: whether iMovie attempts to keep the visible portion of a clip intact when changing the duration of the transition, or grabs footage from surrounding clips to maintain the project's overall duration. This is important if you're synchronising video with music (like a music video) or an additional audio track.
Back to the timeline
One significant change is the new Single-Row View, accessible by clicking a button in the Project browser. Instead of running the project in multiple rows like a paragraph of text, the view maintains one row that scrolls horizontally. Wait, that looks familiar! It's just like a traditional video editing timeline, the lack of which was one of the main reasons iMovie HD users shunned the new incarnation. Click the Swap Events and Projects button in the toolbar, and you've got the timeline in its familiar place at the bottom of the screen.
It's important to point out that the new People Finder feature uses face detection technology, which notices when a human is in the shot and not face recognition, which identifies specific people. Even so, it's helpful to be able to quickly view all footage containing people when you're searching through hours of footage, but keep in mind that analysis can take some time and analysing just for people is faster than for stabilisation. iMovie's clip thumbnails are especially ill-suited to this task, because someone could appear in 10 seconds of footage that is otherwise dominated by scenery. Unless you've expanded the icon view to display more frames, you may not see that section without scrubbing through the entire clip.
I had no troubles with People Finder, and even noticed that it correctly ignored a plastic action figure. The feature takes advantage of the under-utilised keyword tagging capabilities of iMovie (which appear when Show Advanced Tools is enabled in the application's preferences). With a little time and patience, you could create keywords for people who appear in your movies, use the People Finder to narrow the footage, then tag the person-specific keywords to the appropriate sections.
Formats and performance
If there's any portion of iMovie '11 that might disappoint longtime iMovie users, it's the fact that not much has changed with the program's core engine. Video shot as interlaced (such as 1080i, where the camera records every other horizontal line in every frame) can display combing artifacts.
Also, iMovie does not edit AVCHD video natively, but still transcodes imported footage into AIC (Apple Intermediate Codec) format for easier editing. This is presumably in order to maintain smooth interactivity when editing.
AVCHD manages to fit a lot of high definition video into a relatively small space due to the way it compresses the video: after capturing a full image frame, many subsequent frames include only the pixels that have changed. Editing the footage in real time requires more computational power to fill in the rest of the frames, which can lead to sluggish performance. I encountered this when reviewing Adobe Premiere Elements 9, which does handle AVCHD natively. So, as with previous versions of iMovie, importing AVCHD video requires transcoding time before editing, rather than slowdowns during editing.
iMovie also does not import raw AVCHD files, except when connected to a camera or when you've used iMovie's archive feature to offload the contents of a camera to the hard drive for import later. To import the native compressed files directly, you'd need to run them through a conversion utility such as VoltaicHD.
On the other hand, iMovie '11 does now support video shot at 24p (24 progressive frames per second) without converting the rate, as the previous version did. The exception is when you're mixing video of different frame rates within a project, in which case the first clip added to the project determines the frame rate used. When clips in the Event browser have different frame rates than the current project, a yellow indicator badge appears with the rate. In practical terms, the badge is for informational purposes only, but it can help you choose footage with the same frame rate from multiple events, such as when you want a project to be entirely 24p.
One intriguing addition to iMovie '11 is a Rolling Shutter fix option. Here's the problem: cameras that record to a CMOS sensor capture each frame in horizontal bands starting at the top of the frame and moving to the bottom. Although each frame is captured quickly, camera motion can often cause a "jelly" effect, where objects seem rubbery.
After a clip is analysed for image stabilization or to identify whether people are in the frame, iMovie can apply a rolling shutter fix in the Clip inspector. It can apply four levels of correction (Low, Medium, High and Extra High), and in this case results will vary depending on the footage. But if you encounter footage that's particularly "bendy," it's worth letting iMovie take a crack at fixing it. The fix is mathematical, so iMovie doesn't need to re-analyse or render the clip. Another simple but useful feature is the Mark Camera Pans option, which makes it easier to identify sections of stable video or changes in subject matter.
iMovie '11 has a few standout features that show off its capabilities, like Movie Trailers, long awaited sound editing and One Step Effects. But there are also plenty of other enhancements indicating that this release has depth and character, like the return of a traditional timeline in Single-Row View, a fix for rolling shutter artifacts, the People Finder feature, audio effects and even little things like the Side by Side and Blue Screen edits.
Although iMovie doesn't edit AVCHD natively, I'm inclined to consider it only a partial negative. I'd much rather give up transcoding time at the import stage and edit with few interruptions, than have to stop and render portions of the movie (an aspect of iMovie HD that I'm happy to leave behind). It is unfortunate that people working with interlaced footage still run into problems and need to either encode outside the application or consider moving to Final Cut Express or other editors to get the best quality.
However other additions, such as exporting movies directly to Vimeo and Facebook, make iMovie '11 a solid upgrade, especially given the lower price of iLife '11, compared to previous releases.