Basic frame rate questions

[Mark-P]

1.) Is 60fps considered a high frame rate, or are only 120, 240fps, etc. considered HFR?
2.) Does 60fps have anything to do with the fact that it is double the frame rate of 30fps? Do you also use 60fps when you need to do slow motion for a 24fps project?
3.) Do cameras typically shoot lower quality/lower bitrates when shooting 60fps vs. just 30 or 24fps? Why not just always shoot in 60fps in case you decide to slow something down later?

Thanks.

 

[NorBro]

(1) It is by some, but not by everyone as people also do shoot 60p for regular real time acquisition (sports, some shows, etc). Personally, I consider anything above 100p/120p HFR.

(2) Not sure of any direct correlation. Most people shoot 60p to produce slow-motion in a 24p timeline (50p/25p in PAL land). Some cameras over-crank internally and produce slow-motion ready files for you, i.e. you'd set your camera's framerate to 60p but your timeline settings would be 24p. When you would playback the footage on your computer, they would be 24p files that are in slow-motion. 60p files wouldn't be and you would need to slow them down in your NLE.

(3) Yes, they do. 60p especially at higher resolutions is more information to process and it's simply not offered in most cameras either because of hardware limitations or corporate decisions (price, other models). Shooting in 60p and playing it back in real time on a 24p timeline will not look the same as materiel captured in 24 frames per second, which is considered the gold standard film framerate. Frames would be dropped and the motion cadence and the motion blur would look different.

 

[Mark-P]

1. Why do some shoot 60p for regular real time acquisitions? What is the advantage of doing this if it is not slowed down?
2. Does shooting 60p generally require more light or different settings to produce the same exposed video as shooting at 24p?
3. When does it make sense to shoot 120fps or 240fps if a camera supports these HFR options? If planning to shoot footage for slow motion and the HFR options produce smoother slow motion, what things do you need to consider before going from 60 to 120 or 240?

Thanks!

 

[NorBro]

1. It's mainly about the look. 60p simply captures more frames per second. For sports, it's ideal as you're moving the camera a lot (most likely panning relatively faster) and the quick motion appears smoother. Shows may desire the same look...where everything appears more real some may say.

2. Your shutter will (or should) increase so you'll lose light. 1/120 would be 180°.

3. These days anything and everything has slow-motion it. Video creators may choose to use it in music videos, films, commercials, sports of course; the possibilities are endless. 60p slow-motion on a 24p timeline provides you 40% slow-motion. The main things you need to consider when choosing the framerate is the speed and exposure. Some projects may benefit from moderate slow-motion and some from a much slower look. When you gain experience shooting slow-motion, you'll have a better feeling for what you like and when you'd use it. There is no perfect answer...just experience shooting various content and constantly learning. The shutter speeds with 120p/240p will increase and therefore affect the light input, so you'll have to use lights and/or fast lenses.

A lot of filmmaking (video) is about experimenting.

A combination of hardware, camera settings, light and what you are pointing the sensor at all can have an effect on the end-result.