Let's take a look at how to take slow-motion videos on the HTC One M8
* First, slip into video mode. (Hit the button with the four circles on it.)
* Now look for the video mode button. It'll be between the three-dot overflow and the ISO settings.
* Tap it, and then choose the little walking guy option. You'll see "Slow motion video" flash on the screen.
* Now all you have to do is hit the video record button.
* Once recording begins, you'll notice that it's recording four times faster than you're used to, and the elapsed time will count up by 4 seconds instead of 1 second.
* Once you've got your slow-motion video, you can edit it. Just go into your gallery, open up the video you want, then hit the overflow button and choose "Edit."