A Camera can be set to film on different frame rates. It`s good to know why you are using a particular frame rate so you can use it to achieve a different psychological effect on the viewer. Use it wisely, it makes your final product look very interesting. Let`s go from the basics and explore the differences.
Frame rates: How many image are captured per second. This is different to shutter speed which I will cover later on.
Example of different frame rates.
It captures 15 frames per second. You can use this to create a fast forward effect in the post production. When you put the 15fps footage on a faster frame rate edit line, such as 24fps, it will line up more image per second creating a blur to the movement. Great for car head lights and hyper lapse.
This achieves a similar look to the cinema. It has a slight motion blur on normal speed and this is something we have gotten used to. It`s great for conversation shots and little movements. Be careful because you can not do a buttery slow motion with this frame rate. You will need to record with higher frame rates than this. If you try to create a slow motion, it will try to do so by duplicating frames. Image will look jittery.
This has more realistic look than 24fps because the movement looks smoother as it captures more image in one second. It has a realistic look like news. By the way, iPhone shoots on this frame rate. You can achieve a slight slow motion effect when you put it on 24fps timeline by slowing down the footage to 80 percent.
48fps - 60fps
The image is very crisp due to more image recorded per second. Great for slow motion purposes. This is what you would see on football games and video games. However, the footage will be much heavier compared to 24fps etc. It will use up space on your memory cards, HDD and consume time in post production. Great for slow motion of people laughing and clapping hands. The slow motion looks smooth and graceful. Music video uses this rate to slow down the image to sync the lip. The lips are synced to the lyrics but the body movement is slower and it has a dramatic effect.
You can create a stop time effect with this frame rate. If you record at this rate with handheld, it will look very shaky on the timeline. However, when you slow it down it becomes perfectly stable.
One thing to be careful is shutter speed is not the same as frame rates. Shutter speed is how long the exposure of each picture is. Therefore, 1/60 shutter speed is not the same as 60fps.
Frame rate; Number of pictures per second
Shutter speed: The amount of time the camera opens and captures light during each frames.
KEEP THE SHUTTER SPEED ABOVE THE FRAME RATE. If you shoot on 60fps, but if the shutter speed is 1/30, then you only get 30 images per second.
When choosing the frame rates of the camera, you need to know what the base project frame rate is. If shooting a film, the editing time line maybe 24fps. If NTSC TV Broadcast then the editing timeline is30fps, if PAL region it might be on 25fps of timeline. So, if you shoot 60fps and show it on 24fps timeline, It will give you impression of slow motion. This is because you have too many frames in each second in the original footage and they get spread further on a 24fps. The more frames per second you record, the slower it looks if you put it on a lower frame rate project.
I am a documentary/News cameraman based in London.