Slo-mo video works best when it slows down at just the right spot. You can edit where the slow motion starts and stops with a few taps in the Photos app.

To learn more about this topic visit the following article:
Use camera modes on your iPhone, iPad, and iPod touch: https://apple.co/2uziK2K
How to edit videos on your iPhone, iPad, iPod touch or Mac: https://apple.co/2SryBbm
Manage your photo and video storage: https://apple.co/31FFtGB

Additional Resources:
Contact Apple Support for iPhone: http://apple.co/iPhone

To subscribe to this channel: https://www.youtube.com/c/AppleSupport

To download the Apple Support app: http://apple.co/2hFtzIv

Apple Support on Twitter: https://twitter.com/AppleSupport

For more videos, go to Youtube Apple Channel