How frame rate and shutter speed affects your video
A few weeks ago I wrote an article for Wipster.io titled Debunking the 180-degree shutter rule where I boldly stated that the 180-degree shutter rule is a myth! As expected, it caused some noise in Facebook groups and other forums.
Some of the readers said that they thought the video examples (a spinning bicycle wheel) were not proving my point. I agree that it wasn’t the best example, so I made a new video that shows how motion smoothness and motion blur is affected by frame rate and shutter speed. This time with a bouncing tennis ball.
The video is 50 fps, so for perfect viewing, view on a screen with a refresh rate of 50 or 100 Hz, but the difference is pretty obvious on a 60 Hz screen too. Also make sure that you’re actually watching the full quality 50 fps video.
The point of the video is to show that motion blur looks natural when the shutter speed is close to 1/50 (or 1/48) second, and will look more unnatural the more you deviate from this shutter speed. I shoot at 50 fps to avoid the stutter/judder that comes from 24 and 25 fps video. In my opinion, 50 fps yields much smoother and more natural movement.
The new video
Here’s a video of me bouncing a tennis ball with a racket (yeah, it’s a squash racket, but that’s what I had at hand). See how the motion blur for 1/50 second is exactly the same, and looks good, for 1/25 second and 1/50 second shutters—you may want to add: of course. I find the smoothness of 50 fps so much nicer to watch than the stuttery/jerky/juddery 24, 25 and 30 (29.97) fps.
I guess it’s less “filmic” or “cinematic” since it doesn’t replicate the jerky movement that cinema has had for decades, but I don’t want my footage to look “cinematic”, I want it to look good. In my opinion, the 50 fps 1/50 second (360 degree shutter) looks best.
Shot by Dag Frode “One-take” Olsen on a Canon EOS C300 Mark II.
Jarle’s verdict: 25 fps looks best at 1/50 second, and so does 50 fps, but 50 fps at 1/50 second is smoother and more natural looking, so that’s my choice. You’re allowed to disagree.
Is the 180° shutter a myth?
Some commented (after reading the Wipster article) that it’s not a myth. I will have to disagree, since The Oxford Dictionary says that one meaning of the word Myth is “A widely held but false belief or idea”. In this case that widely held but false belief is that you should always use a 180° shutter. You shouldn’t–if you shoot 50 fps for 50 fps playback, use a 360° shutter. If you want natural looking footage, that is. As the original article says, there are many reasons why you wouldn’t always want that.
Please note that this advice (360° shutter for 50 fps video) is only valid if you plan to show the video at normal speed. If you shoot at higher frame rates than 24 fps for slow motion purposes, then other rules apply, and you should probably go for a 180° shutter.