Jyunte
 Second Officer
Flight distance : 2103150 ft
United States
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StanfordWebbie Posted at 2018-1-29 17:58
Nice work. I agree with Brian88 on transitions. I used to use them a lot, then read a professional who advised against them. You rarely see any in professional movies or videos. I've stopped using transitions since. Also, I watch these videos at full screen on my 28 inch monitor. Your video is a bit "jerky" throughout. I'm not sure why, but I recall reading once that shutter speed can cause that (and I think it was "too fast" shutter speeds, although that sounds counter intuitive). Anyway, take another look and see if you agree. Compare to other videos on this forum and I think you'll see that yours is doing that more than the others.
Fast shutter speeds = Jerky footage:
(The following assumes there's adequate light for each scenario)
When you take a photograph you are freezing a moment in time.
- Scenario 1: If the shutter is open for a long time, anything in the frame that is moving (or everything in the frame, if the camera itself is moving!), will be blurred when the shutter closes. This results in, you guessed it, blurry videos, where every moving objects is blurred.
- Scenario 2: If the shutter speed is very fast (a relative term), then you are freezing all movement of all objects in the frame. You're also freezing all movement of the camera. This looks strange, because the human eye/brain doesn't see moving images as a series of sharp, individual images with all movement frozen. The fact that there a little blur helps us recognize that objects actually are moving. When that motion blur is missing, the video looks staccato/jerky... There's nothing joining one image to the other... Moving objects just disappear from one area of the screen, and reappear instantly somewhere else...a footstep away! If the camera is moving, because the drone is flying asking a path, then the entire image is disappearing and reappearing every frame, resulting in jarring, jerky video.
- Scenario 3: If the shutter speed is open for just the right amount of time, based on how long the sensor is actively capturing the image, then there will be both sharp, in focus objects, and slight blurring of objects that are moving (because the image is captured progressively from the "top" to the "bottom" of the sensor over the duration of time the sensor is active). This is what the eye/brain expects to see.
A frame rate of 24fps is the slowest frame rate which mimics how the eyes/brain perceive movement... A sharp image, followed by a lingering after image (persistence of vision).
At 24fps, if you expose the sensor for half of the time that the sensor is actively capturing the image (1/48 second), then your capturing images which contain both sharp objects, and a small amount of motion blur... Almost exactly what the eye sees naturally.
If you increase the frame rate and increase the shutter speed accordingly, so that it's still 1/2 frame rate, you begin to freeze all motion in the individual frames again, leading to the staccato/jerky motion effect described in scenario 2, above. So, to keep the video smooth and natural looking, keep the frame rate at 24 or 30fps, and the shutter speed at 1/50 or 1/60 second respectively. Of course, if you want a staccato effect, like the scene at the beginning of Saving Private Ryan, then throw away this 180-degree rule.
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