Filming a timelapse sequence with your iPhone is easy, right? Just slide it over to 'timelapse', bang it on a tripod and hit go!
Well, yes that will get you a timelapse, but how long will the final video be? That's a pretty important thing to know if you're incorporating the shot into a larger project.
This extract from MatJoez.com describes how your phone works out the final length and dynamically changes the frame rate based on how long it's been filming the same clip:
With a normal timelapse, you would select your interval and your shooting length, and then you can calculate your clip length.
The iPhone does this differently, by using so-called dynamic intervals.
If you are recording a timelapse under 10 minutes, then the interval will be 0.5 seconds, or two frames per second, resulting in 15x speed increase compared to real-time.So 15 seconds of recording will be 1 second of footage because 15 seconds of capture at 2 frames per second gives you 30 frames. Divide that by 30fps and you get 1 second of timelapse footage.If you go over 10 minutes of recording then your interval will switch to one frame every second, and the iPhone will remove half the frames you recorded before 10 minutes to keep the shot length about the same.
Shooting over 20 minutes your interval is one frame every two seconds.
Over 40 minutes your interval is one frame every four seconds.
Over 80 minutes your interval is one frame every eight seconds.
This results in a 15, 30, 60, 120, or 240x speed increase compared to real-time video.
Make sure to read the full article here for all the details plus, some recommended app that give you more control.
Comments
Post a Comment