Read this and you will know why
Did you just get your new shiny iPhone 8, iPhone 8 Plus, or iPhone X? Me too! Well, the first thing I did was go to change my settings so that I could record video at that glorious 4K at 60 fps setting! By default, Apple sets to only 1080 at 60 FPS, which is nice, but you really should record everything at 4K if you can.
What was more surprising was the fact that the slow-motion recording defaults to only 720p at 240 fps! That will totally not cut it for me. So I tapped on Record Video and was quite surprised when I didn’t see any 4K/60fps option!
Same thing with the slo-mo settings. It only had 1080p at 120 fps instead of 240 fps. Where in the world were the higher resolution options!?
Luckily, I happened to tap on Formats (from the first screenshot) and saw that the iPhone 8 Plus was set to Most Compatible. Right under that it clearly states that if you use Most Compatible, it will use JPEG and H.264 formats, but it will drop the 4K 60 fps and 1080p 240 fps recording options.
Whoops! I choose High Efficiency, which uses the HEIF and HEVC formats and the options were back!
The higher resolution option was also available for slow-motion video too. So, if the higher resolution options are missing on your iPhone 8 or iPhone X, you now know why. Just change the format for the recordings and they will come back. Enjoy!