Slow motion is everywhere. Almost every video, movie, or show, includes a slow-mo sequence at some point. It is as ubiquitous as a dolly in/zoom out shot. Naturally, this means every beginner feels drawn to suing this technique to add some flare to their first projects. It really isn’t hard to learn when you’re just learning your way around a camera and it will give a little extra something to amateur projects. But actually, good slow motion is not that easy to make if you’re not sure about what you’re doing. Make sure to avoid these mistakes to evade an easily preventable headache in your videography career:
Using the Wrong Speed
The first thing everyone learns about slow motion is that the higher the frame rate, the slower the footage. The second thing they learn is that cranking the frame rate as high as possible will actually result in crappy slow-mo. Not only is ultra-slow motion hardly ever necessary, it just doesn’t look good. Subjects will have a weird glow to them or a weird ghost shadow following them around and you’ll be lucky to get any sharp images that way. What’s worse, it will be really hard to make it look professional in post-production regardless of your editing skills and software.
What you need to be doing is math, sad news for those who hated it in high school, but in the visual arts, it’s used a lot. Your shutter speed needs to be twice whatever your frame rate is. This means that shooting a scene at 40 fps should make you set your shutter at least a 1/80. That way you’ll get rid of any ghost images and weird lights.
Not Correcting the Lighting
A common issue with slow motion is underexposed images. This happens when either the videographer is taking pictures way too quickly not allowing enough light to go through the shutter, or when they corrected the speed to make it a lot faster but didn’t account for the amount of light they were going to lose when making that correction.
In the first case, all you’ll need to do is slow down. In the second case, it’s a bit more complicated, you might need to add some artificial lighting to properly illuminate your subject. Be careful, though, not every light works. Some lights, especially fluorescent lights, tend to flicker. Even if you can’t see it with your own eyes, your camera might pick it up. Whenever you add lights, make sure to do a test run and check the results before actually shooting.
Using Slow-mo to Fix Bad Footage
Here’s the thing, if you did a handheld shot, it will look like a handheld shot. No matter how much slo-mo you use. It is true that slowing footage down works well when trying to hide shaky images, but it’s not something you should get in the habit of doing. Especially because slow motion is supposed to be used to give viewers a sense that time has stopped and disrupt their perception of reality. Using it to cover unsteady shots makes it lose its power.