Almost two weeks ago, OnePlus released Open Beta 3 for the 7T. Though the changelog at the time was pretty light, it turns out there was a hidden feature in the release that didn't get mentioned. The beta update also delivered 720p 960 FPS slow-motion video recording,

The new feature works via interpolation — which is to say, it's not actually capturing at 960 FPS, it doesn't have the hardware to do it. Instead, it's capturing footage at 480 FPS and interpolating the missing frames. While it won't be quite as good as "true" 960 FPS, the approximate effect should be very similar — at least, if it works. We've got one report from a reader (Thanks: donjamal) that the new feature only works for about a second of video, though that may vary.

Left: 960 FPS option in the latest beta. Image via u/sneakerspark. Right: Pre-existing 4K 30 fps ultra-wide video recording.

Although some are reporting that the OnePlus 7T also picked up 4K 30 FPS video from the ultra-wide camera, so far as we can tell, that's a feature the phone already has outside the beta release. A device on-hand that's not running the beta can record 4K 30 FPS video using the ultra-wide camera right now, and at least one early hands-on video implies the feature has been around for a while — though the 7 Pro picked it up in an update later. 4K 30 FPS ultra-wide video may have rolled out earlier via some other mechanism.