You can find/update this Beta in the Store right now. Here's the changelog for this new v5.45.6 (the basic Lumia Camera for these devices is still on 5.0.2.54):
- Living images are automatically only captured for scenes with motion
- Updated capture and autofocus behavior
- General fixes and improvements (including MP4 encoding)
The Beta installs separately to your main Lumia Camera Classic and Lumia Camera 5 apps (if installed, and yes, potentially confusing, but we're talking enthusiasts here and you guys know which is which!!) The MP4 encoding issues meant that I hadn't been able to shoot and edit video in iMovie and now it all seems to work fine. Curiously, the update to the Beta seems to have fixed the issue for the standard Lumia Camera (v5) application too, so presumably a codec has been tweaked under the hood and both apps benefit.
I couldn't see any difference in capture behaviour - any help from you guys in the comments?
The Living Images tweak makes a lot of sense - I tended to leave this feature off because it seemed such a waste capturing extra files for what was almost always a static scene. Now we can leave it on all the time?