Whether you’re shooting on a cellphone or a RED cinema camera, picking the right frame rate is essential for a good finished video. Here’s a guide to choosing the right frame rate for any purpose.
In this video by Potato Jet, there is an in-depth explanation of how to select the proper frame rate, as well as what steps to take in editing to achieve effects including a filmic look, pseudo slow motion, and full-on slow motion.
I appreciated the brief history of frame rates, which went quite a way to explaining the difference between PAL and NTSC frame rates. It goes quite a way into clearing up any confusion over the different rates. As a good rule of thumb, he shoots 24 frames per second, which matches my personal preference.
A great tip was to shoot 30 frames per second video, but then edit in a 24 frames per second timeline. This provided a very subtle slowing effect, not as conspicuous as typical slow motion, but still helpful in mellowing out the footage. I’ve used this with footage from a gimbal, which can help with the slight shake that can make it past the gimbal.
Like many of Potato Jet’s videos, this one does a great job of breaking down videography concepts in an easy and informal manner.
Lead image courtesy of Jacob Owens.
Ok.
We have that 1% drop in frame rate because of our electrical system in the US.
It operates at 60 hz.
The 60 hz wave would cause hum when true 30 frames per second was used in old TV cameras and equipment because those waves would sync every few seconds and exchange energy.
29.97 frames per second is called 30 frames per second drop frame vs non drop frame which is actually the full 30 frames per second, or non drop frame.
That means it drops a frame every ten frames to avoid that sync issue.
This is important only if you are broadcasting your video on TV in the US.
If you record in 30 non drop frame for any length of time, like a half hour show, your show will run long in broadcast and will end up getting the last minute of it cut off because it ran long.
So you record, or edit in 30 drop frame AKA 29.97 if you're final product will run on broadcast.
Most editing software has 3 types of interpolating data at different frame rates.
That will either produce choppy playback of frame rates slower than the editing project's frame rate, or more smoothly depending on what type of interpolation.
They may be:
Frame sampling - choppy
Frame blending - less choppy
Optical flow - very smooth
The later 2 create new data to make in between frames to smooth out the image between the actual frames.
Also shutter speed/shutter angle is critical to creating motion blur that is often associated with 24p.
I know there are a lot of 24p aficionados out there, but since no film is played back via film in a projector anymore, it's not really the same "Cinematic" effect everyone strives for.
By the way, 24 frames per second was chosen way back by film makers because it saved money on film stock, but still gives the illusion of smooth motion. Any frame rate slower than 24 will appear choppy to the human eye.
I think 24fps was chosen for a variety of reasons... sure, it kept costs lower than higher framerates, but it also satisfied Edison's minimum 46Hz requirement (double shutter on a 24fps projection results in 48Hz), and it worked out better with Vitaphone playback. A 16-inch Vitaphone record (played at 33 1/3 rpm) matched the 11 minute playback time of a reel of film projected at 24fps.