Smooth light trails / Interlaced video on android?

[RedRaven]

Hello guys!

Feel free to aim me in a direction of a better place to ask this if I'm in the wrong place here. The situation is this: I need help/advice with creating smooth light trails in a video. Basically, this (not me or my video):
https://www.youtube.com/watch?v=5-xLDVILtMY

I managed to learn how to work with the Echo effect in Premiere with success. Editing is no issue. Apparently the video source is.

I have tried with two kinds of footage - an interlaced video from a camera (no idea what kind) and progressive video from my mobile (P30 Pro). With the interlaced video, I can create a beautifuly full smooth trail. With the progressive video, the trail is all choppy as apparently half the motion is missing between frames.

Is there an app that can shoot interlaced video on mobile? Are there settings I can try to change to get a better effect? Am I out of luck and need an actual camera? What do, internets, what do?

Thank you for any advice you can give!

[smrpix]

Interlace effectively doubles the frame rate by using two fields for every frame. (That's not quite a technically correct explanation, but it describes what may be happening here.)

Try increasing your framerate.

That phone will do 1080p video at 60fps and 720p video at 960 fps. Did you try those modes?

Also, you might try combining the optical flow interpolation with the echo effect in Premiere.

[RedRaven]

Try increasing your framerate.

Or, you know, locking the shutter to the actual framerate - 1/30.

So if anyone wants to know what I should have realized sooner - say there are 30 frames in a second. If I have a faster shutter, say, 1/60, it will still be open only 30x a second, but will close before the frame is over. Thus only capturing a part of the trail movement. Adjusting the shutter to the framerate means the shutter will be capturing the light during the full frame duration. And my trails won't have any gaps.

Duh.

Also, thank you for replying. It helped.