Can I shoot at 48FPS instead of 24FPS with no negative differences other than size?

[Lee M]

I want the option of going slow motion but don't want to jeopardize anything in the footage other than file size. If I change my frame rate from 24fps to 48fps would there be any negatives? Would I want to keep the shutter speed at 1/48 or go to 1/96?

I will most likely end up using every second frame (rendering at 24fps) but if there is no harm I feel why not. If I raise the shutter speed I understand that I would require more light so curious if I can keep it at 1/48 and then get the exact same results that I would have if I just shot at 24fps 1/48 shutter.

 

[Owen Rennie]

Unless audio is important i shoot at a higher frame rate when possible so can speed ramp in post.. "real time to slow mo". Best you stick to 180 degree shutter to be safe however you can choose whichever shutter speed suits the look your going for. For example if you want a real smooth flowing look, I guesss you could say like shooting a ballarina than 360 degrees (24fps with 1/24th) may work for you or when I shoot martial arts I want a "crisper sharper" look I'll shoot a faster shutter say 24fs with 1/96th. Do some tests and see what works. But like I said stick with 180 (double the fps) and you'll never have a problem! Hope that helps a bit

 

[Owen Rennie]

Also the higher the frame rate the higher compression. However 48fps compression (depending on camera) shouldn't be a problem!

 

[Nick Morrison]

I want the option of going slow motion but don't want to jeopardize anything in the footage other than file size. If I change my frame rate from 24fps to 48fps would there be any negatives? Would I want to keep the shutter speed at 1/48 or go to 1/96?

I will most likely end up using every second frame (rendering at 24fps) but if there is no harm I feel why not. If I raise the shutter speed I understand that I would require more light so curious if I can keep it at 1/48 and then get the exact same results that I would have if I just shot at 24fps 1/48 shutter.

Depends on how fast the motion is.

We do mostly portraits, but for their "hero" moments, we love to shoot 48fps, the head turns looking up. But I hate sacrificing a stop, and also hate having to change the blackshade on an Epic Dragon, so we just keep the shutter at 1/48 (from 23.98) when we're at 48fps. For slow moving things, it's not even noticeable. A 360 shutter at 48fps is not as "soft" as a 360 at 23.98. It's totally usable.

But again, if we were filming sports or something fast...we'd def stick to 180 (ie 48fps at 1/96), but it's not necessary.

These are all creative tools.

 

[Todd T]

+1 to Nick's comment.

180 degrees at 24 FPS is the same as 360 degrees at 48 FPS, so you will keep the same light levels, t-stop, and motion blur characteristics as if you had actually shot at 24 fps.

The only time you would change the shutter speed is if you need to compensate for motion blur.

If you change the camera project FPS to 48, you will also be able to capture in-camera audio as well, so when you drop it into a 24fps timeline (without re-interpreting the clip) it will look and sound like a normal 24fps clip with the ability to ramp the speed as you prefer.

 

[Stephen Pruitt]

I don't think Todd's comment is correct. 180 degrees at 24 has very different motion-blur characteristics than 360 degrees at 48. It will have the same exposure, but that's it.

Stephen

 

[Blair S. Paulsen]

48fps at 360° and 24fps at 180° will capture the same amount of motion blur during each 1/48 of a second exposure. If you decide to remove every other frame for a 24fps "pull" from that footy, the deleted frames are essentially the same as if the shutter was closed during that 1/48th of a second. This is a strategy I employ when the hero deliverable needs to match 24fps@180° material already created, with the added benefit of having a 48fps version for time remaps and other VFX use cases.

Shooting, and viewing, 48fps at 360° will have different motion blur characteristics than shooting, and viewing 48fps at 180° as the shutter is open 1/96th of a second per captured frame rather than 1/48th. Note: don't underestimate the influence of years of watching 24 and 30fps material on the viewer's experience when watching 48fps material, regardless of motion blur characteristics.

Cheers - #19

 

[Nick Morrison]

I don't think Todd's comment is correct. 180 degrees at 24 has very different motion-blur characteristics than 360 degrees at 48. It will have the same exposure, but that's it.

Stephen

Not in our experience. It's the same shutter angle.

180 degrees at 23.98 is 1/48. 360 degres at 48fps is 1/48.

Same shutter angle. Same blur. Same everything. Just different film "speed".

 

[Nick Morrison]

48fps at 360° and 24fps at 180° will capture the same amount of motion blur during each 1/48 of a second exposure. If you decide to remove every other frame for a 24fps "pull" from that footy, the deleted frames are essentially the same as if the shutter was closed during that 1/48th of a second. This is a strategy I employ when the hero deliverable needs to match 24fps@180° material already created, with the added benefit of having a 48fps version for time remaps and other VFX use cases.

Cheers - #19

Exactly. The advantage of shooting 48fps at 1/48 is that when sped up 2x (to simulate regular 23.98) it actually looks normal due to its "standard" 1/48 shutter angle...and doesn't "step" or "stutter" as it would if it had been shot at 1/96.

This is one of the beauties of shooting 48fps at 1/48.

It can serve as slowmo...

And then when sped up 2x, can also pass as regular footage pretty well.

Nice combo package, for slower moving things.

 

[Scot Yount]

Depends on how fast the motion is.

We do mostly portraits, but for their "hero" moments, we love to shoot 48fps, the head turns looking up. But I hate sacrificing a stop, and also hate having to change the blackshade on an Epic Dragon, so we just keep the shutter at 1/48 (from 23.98) when we're at 48fps. For slow moving things, it's not even noticeable. A 360 shutter at 48fps is not as "soft" as a 360 at 23.98. It's totally usable.

But again, if we were filming sports or something fast...we'd def stick to 180 (ie 48fps at 1/96), but it's not necessary.

These are all creative tools.

Great insight. Simple math but well put.

 

[Stephen Pruitt]

Interesting. Very interesting.

Stephen

 

[Satsuki Murashige]

Another option would be to split the difference in shutter speed between 1/48 and 1/96, and shoot 48fps @ 1/72. This would give you slightly more motion blur @ 48fps and slightly less @ 23.98fps, which might be a good compromise depending on the subject matter you are shooting. Though if you are shooting under non-flicker-free lighting units like fluorescents or LEDs then this could be a problem.

 

[David Mullen ASC]

I don't think slow-motion shot with a 360 degree shutter looks that great -- I've done it in the past, like shot a slow-motion shot at 60P with a 360 degree shutter and it was too smeary in motion to look good as a slow-motion shot.

It would be better to shoot 48 fps with a 180 degree shutter unless there is nothing moving in the frame (but then, why would it matter if you shot it at 24 fps or 48 fps?) and either live with the look of 24 fps with a 1/96 shutter time (same as shooting with a 90 degree shutter angle) or do some frame blending to create a smoother 24 fps version.

Or split the difference and shoot with a 240 degree shutter angle.

 

[Lee M]

There is not a lot of fast movement in the shot, in fact, I want the camera movement to be extremely slow. Its a 60 second shot with the Dragon on a Ronin that basically pans and tilts around a person that is relatively still yet a bit of movement (I might have her do the movements more rapidly so they don't appear like they are in slow motion. I basically want the camera movement to appear very slow and consistent and feel that the Ronin may be a tad too fast even on speed 1. Just want the option without affecting anything if I decide to just use 24.976 @ 180 shutter.

 

[Owen Rennie]

Can you just test it? Try them all and see what you like

 

[Ketch Rossi]

For Fashion and other specialty Corporate & Science related work, I change the Shutter Angle to 90˚or 45˚ to intentionally eliminate as much Motion Blur as possible for specific reasoning and Frame Pulling, but when possible I much prefer to shoot different sequences with different Shutter Angles, one for the Frame Pulling and one for the actual Film footage, especially when doing Slow Motion.

But it does not works always the same way for any given shot, especially when in Fashion Shoot with highly detailed Clothing and or shooting extremely complex Science related Corporate Projects, then the Blur needs to be effecting the shots as little as possible so Shutter Angle needs to be adjusted accordingly.

In general, 180˚ when shooting 48fps or 60fps to be played back at 24fps looks much smoother and pleasing to the eye.

 

[Lee M]

From my understanding, HDRX only increases the shutter speed correct? I am guessing it may not work though since I cannot use 360 degree shutter for HDRX. How many stops HDRX would you recommend if I want to get as close to 1/48 as possible at 48fps as well as have the option of a higher shutter at the same time.

 

[Marc Wielage]

Shooting, and viewing, 48fps at 360° will have different motion blur characteristics than shooting, and viewing 48fps at 180° as the shutter is open 1/96th of a second per captured frame rather than 1/48th. Note: don't underestimate the influence of years of watching 24 and 30fps material on the viewer's experience when watching 48fps material, regardless of motion blur characteristics. \

It's interesting to note in the recent Billy Lynn's Long Halftime Walk 120fps presentation, they reportedly used RealD Truemotion to add and change motion blur in certain sequences. There are several ways to introduce motion blur, but I would bet this one is extremely precise (though not cheap).