I had both the Lumia 950 XL and iPhone 8 Plus in a jig to keep them stationary with respect to each other, though this did compromise the 950 XL's stereo audio in that one of the microphones was essentially obstructed by the jig and adjacent iPhone - so take the imbalanced audio and occasional scratching sounds with a pinch of salt - it's just how I had the phone mounted.
Both phone cameras have OIS plus EIS (Electronic/digital stabilisation, essentially using accelerometer inputs and/or frame analysis to make the output super smooth) - ignore that aspect of the commentary, in which I wasn't sure about the iPhone's EIS and imply that it's Lumia only. EIS of various kinds is definitely in place on the iPhone (as you'd expect) and applied after outputting the preview to the viewfinder, which is why I couldn't spot it properly at shooting time in the real time commentary.
Note that all footage is at 1080p deliberately, I've ignored the 4K facility on both phone cameras, partly because not that many people can still stream or view 4K and partly because I wanted to use quite a bit of digital zoom here (and less is needed at 1080p since there's spare 'capacity' on the sensors).
This comparison, for once, sees the Lumia 950 XL comprehensively outgunned:
- the iPhone 8 Plus's sensor is newer
- it has a 2x zoom lens
- it has hardware-based real time noise reduction
- it uses much higher data rates
- it encodes to the new HEVC format (which proved a pain initially when setting this comparison up, but it does deliver excellent results)
Here's the video data point anyway - as usual, click on the 'YouTube' logo, once playing, and you'll be taken off into another browser tab which can be fully maximised - increase the quality there so that you can stream the full 1080p and also see all the resolution available:
The plus points listed above all make their mark, with the iPhone footage superior at every turn. Quite astonishingly clear pixel detail across the frame, decently low noise in the dark of the church (which was a lot dimmer than the footage makes it seem!), lightning fast auto-focus, and so on. While the 950 XL's video frame was dimmer than I'd have liked (remember there's no PureView oversampling help when shooting video) and auto-focus was as rubbish as usual when the light was anything less than good.
The Lumia needn't feel too bad, since technology marches on and video capture is one aspect of phone cameras which has advanced fast than most - these days even £200 phones can shoot 4K, for goodness sake. Simply amazing. Anyone else remember when phones would capture QVGA? And then the Nokia N93 hit the world in 2006 with VGA capture and optical zoom and we thought the future had arrived? Today's 4K video frame is roughly 24 times the number of pixels on-screen as on that original Nokia N93 powerhouse!
All in all, a very definite win for the latest iPhone flagship over the old Lumia, so kudos to Apple here - but then the 950 XL's strong point is stills, arguably? Can't win 'em all, eh?