Trying to settle something about 60fps to 24

[Richard Herd]

I assumed it was dSLR.

Before we can get a dSLR to look filmic, we have to know what a film camera does. That’s why I posted the above math. The next price point and form factor in cameras have setting to let you control the capture more like a film camera. One issue out of our control on dSLR is the video aliasing. They are stuck at 4:2:0. Additionally, we are stuck with the dynamic range. For way more detail on those topics, check out this article: https://library.creativecow.net/galt_john/John_Galt_2K_4K_Truth_About_Pixels/1

That means the thing we can control is the motion blur, which was the emotional content of the shot’s artifice, the image itself (and not the subject). Right there it’s already complicated. Sometimes that content of the format is referred to as “grain structure,” or “gain,” or “blur.” Really there’s no good way to describe it except that article I linked above.

With regard to dSLR capture versus film capture, the thing the dSLRs do not have, but a film camera has is the shutter angle. Here is the best video on that topic: https://www.youtube.com/watch?v=dGYbcvcyBkw

Here’s what happening: shooting on 60fps with a very fast shutter will create the “Saving Private Ryan” look, where we can see each piece of sand during an explosion. The technique was also used on “Hurt Locker” and many other instances. Anyway, when 60fps footage has a shutter speed greater than 1/120 (1/60 * 1/2), there is very little motion blur, if any, on the image, and when that footage is interpreted by Premiere, it creates a funky looking effect. Mr. Galt above does a decent enough job explaining why our psychology considers it funky.

If you feel you need to shoot 60fps to get the footage to look how you want it, then by all means, shoot 60fps. Going from 24 to 60 means the computer interpolates and or duplicates missing frames, but going from 60 to 24 means you are speeding up playback. Right off that bat, that will look better — assuming you’ve set the shutter properly.

Note: this does not even touch lenses!

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[Sean Winn]

Richard,
Thank you for the information and your time, much appreciated…
Sean

[Jp Pelc]

Just saw this in a Google search and I realize I might be late to the party, but I see that people seem to be missing the point of your question. I am currently exploring the option of shooting everything in 60p and still getting a real time 24p look if I want it. From what I can see it doesn’t really work, and while Premiere (or probably any NLE) can drop the extra frames to *sort of* give it a 24p look, it ultimately has a sort of jittery feel and isn’t quite as filmic as actually shooting in 24p. So if it’s not too late, my recommendation is to switch back and forth on the day of the shoot.

[Sean Winn]

Thanks JP – I agree on that.
Thanks for the input

[Richard Herd]

[JP Pelc] “it ultimately has a sort of jittery feel and isn’t quite as filmic as actually shooting in 24p”

Well, I understand the question and I answered with exact detail on what is creating the “jittery feel.” Here it is again: It is the shutter angle. When you are calculating your exposure in motion capture there are TWO things to consider:

1. Frame Rate
2. Shutter Angle.

dSLRs do not have a control for the shutter angle, so when you set the shutter speed, the shutter angle is calculated automatically by the camera. In general, you want your shutter speed to be “times 1/2” your frame rate. Example: 60 fps x 1/2 means set the shutter speed to 1/120. If you go faster than that, you will create the “jittery feel” by making the shutter angle more acute — which may be necessary for some stories. If you go slower than 1/120, then you will create motion blur by making the shutter angle more obtuse — which may be necessary for some other stories.

24p should have a shutter speed of 1/48, because that will give you a 180-degree shutter angle (180/360 = 1/2).
24p with a 1/60 shutter speed, creates a shutter angle of 144-degrees.

60p should have a shutter speed of 1/120, because that will give you a 180-degree shutter angle: 1/60 * 1/2 = 1/120. Because this is how film cameras work, it will create the motion blur our eyes are used to seeing.

60p with a shutter faster than 1/120 will look jittery.

I can imagine what’s happening: It’s a bright day outside, and when you shoot 60p with 1/120 shutter speed, it blows out everything, so you speed up the shutter, and that really means you’ve made the shutter angle very acute, which will actually create the jittery feel. Creatively, that might be a look you need for some things. If you haven’t already invested in neutral density filters, you will need to do that in order to keep the shutter speed at “x 1/2” the frame rate.

🙂

[Jp Pelc]

Yes, I am aware of shutter speed and frame rate and the roles they play in terms of motion and motion blur. Admittedly the clip I tested was shot by somebody else on a DSLR, outside in bright sunlight and looked like it was shot at a pretty high shutter speed. So I have yet to test by shooting a clip at 60fps with 1/120 aka 180 degree shutter. It’s a test I intend to make, however I remain skeptic that 60fps footage can have a 24fps look to it