Video Basics: Frame Rates
Content and Images Contributed By: Richard Newman
There is a lot of confusion for newcomers to the video world about frame rates. We hear a lot of hype about how film is 24 frames per second (FPS) and how beautiful it looks. What we have to investigate is choosing and using the right frame rates for the subject and nature of your video.
Today’s DSLRs have a variety of frame rates you can select from. Here’s a look at some of the standard ones:
These numbers represent the size of the recorded video in pixels (1920×1080) with the frame rate (30) next to it. Let’s look at the selection of 1280×720 60 FPS. 1280×720 is considered HD, while 640×480, below it, is the size of standard television transmission. We also don’t want to confuse frame rate, or frequency with shutter speed. The frame rate is how many frames are recorded during one second, the shutter speed is how long the shutter is open during the frame.
I’ve prepared a short video that shows the visual differences in frame rates. I won’t editorialize too much about which one is better, as that could be debated for hours, but I will make some suggestions and insights and let you choose for yourself.
When I look at the first example, recorded at 24 FPS, the flag appears to me to be richer in color. However, when I pan the camera, I can see more “jitter” from the slower frame rate. Part of what you see is caused by using a DSLR, which utilizes a rolling shutter to capture video. To me, the still frame recorded at 24 FPS looks a little richer in detail.
When I look at the side-by-side comparison between the two videos, one recorded at 1280 and one at 1920, I like the 1280 video a little better because of the 60 FPS that it was recorded at. One of the great things about video from a DSLR is the small size and the portability of the camera. I find that shooting at 1280×720 @ 60 FPS gives me a better looking final product when viewed on my computer.
Using a higher frame rate in recording scenes with action or a lot of camera movement really helps smooth out the overall look of the video. It’s really hard to see a difference unless you are going to project your final image really big, like on a Jumbotron at a sports stadium. Another reason I like recording at 1280×720 is that the file size is much smaller and a lot more manageable. Everything in the editing process works faster for me with the smaller file.
Choosing the right file size and frame rate is the basis of your video work, and it needs to be right from the beginning. Stay tuned, and check back here on the Parallax blog for more great video tips.