Choppy footage problem (60p to 24p interpretation)

M

mikizaba

New member
So yesterday I was trying to get some shots with my new A7s. I've never really cared too much about getting smooth slow mo because most of my older shots were filmed at 30fps. But this time, I tried filming @ 60p w/ 1/125 shutter speed so I could interpret it at 24fps through premiere pro and still have an option to get smooth slow mo where i want it. The slow mo shots were perfect, but the real time interpreted 24fps shots were pretty bad. They were very choppy (partly for the reason I was using a caddy instead of a gimbal I'm assuming.) But the motion blur was horrendously bad. Even though I followed the 180 degree shutter rule, the real time footage was not very fluid like I expected it to be.

So how can I get smooth, 24fps footage in real time using 60p? I am aware that most filmers record at 60fps and interpret it as 24, but the real time footage looks fantastic, and not even close to what mine looked like. Just look at these 2 examples:
=64s

The real time footage looks like normal 24fps with the right amount of motion blur, and the slowed footage still looks smooth as hell.

Is it shutter speed? Is it the smoothness in the way it is filmed? Any tips would be greatly appreciated.
 
Do you have a video example we could check out?

Interpreting isn't the only way to go, I only edit in 60p timelines and then export 24p for all of my videos. I can slowdown to 40% if I wish or leave everything the same, it all comes out 1080p24 and I then upload online.
 
13770098:mikizaba said:
I do.

Here is a collection of clips that were all originally recorded at 60p and interpreted as 23.976 fps. I sped them up 250% so that they would play in real time real time:
https://drive.google.com/open?id=0B9whkdRmeRF6VUJfRGROWmZqbWs

Here is a raw clip that was also recorded at 60p:
https://drive.google.com/open?id=0B9whkdRmeRF6dVJQdkRuMHotUk0
Click to expand...

Well first of all here, i'm *pretty* sure you want to speed it up 240%... I think.

Anyway, the 24p clip looked fine to me, your camera was shaking a bit, which is exaggerated by the 24fps and also any sort of movement is going to look a bit more abrupt at 24fps, thats basically just how it looks.

I think the other videos you referenced to we just filmed very smoothly and in a way that would cause less of this sort of choppy feeling, ie trying to keep the camera as quiet as possible, no jerky pans or tilts, no huge swoops, etc.
 
13770308:eheath said:
Well first of all here, i'm *pretty* sure you want to speed it up 240%... I think.

Anyway, the 24p clip looked fine to me, your camera was shaking a bit, which is exaggerated by the 24fps and also any sort of movement is going to look a bit more abrupt at 24fps, thats basically just how it looks.

I think the other videos you referenced to we just filmed very smoothly and in a way that would cause less of this sort of choppy feeling, ie trying to keep the camera as quiet as possible, no jerky pans or tilts, no huge swoops, etc.
Click to expand...

Agreed.... eheath said everything, going off the sped up shots you really want to speed them up over exaggerate it. The smoother the shot is the better it will look sped up as well.

I usually shoot in 60 to slow it down on a timeline that is at 30 and never interrupt it just use the speed duration anymore within premiere and I can't really tell a difference.
 
Evan's (mostly) wrong. If you want really smooth motion in regular speed at 24fps, you have to just shoot 24fps. Although I do agree that smoother camera movement will help a lot to make the choppiness less apparent.

Dropping 60fps footage into a 24fps timeline will always result in that choppy look to some degree, because you are essentially no longer following the 180 degree shutter angle rule. Think about it: if you shoot 60fps at 1/125 shutter, then drop 60% of the frames to play it back at 24fps, it's the exact same thing as shooting 24fps with a 70 degree shutter.

Also, the a7s doesn't have the best motion cadence to begin with. Can't completely explain why, but some cameras are just worse at rendering motion in a pleasing way. Stept shoots RED which obviously has way nicer looking motion than an a7s. It can also be affected by which codec you use. With the a7s, don't bother with anything except XAVC. MP4 and AVCHD are absolute shite compared to XAVC. I noticed your clips are .MP4 so that could be a big part of your problem.

My advice to you: try shooting mainly in 24fps and 1/50 shutter, and a select few shots in 60fps that you know you'll want to have in slow mo. There's a lot of advantages:

1. You gain 1 1/3 stops of light, which is great for you because you're filming at night.

2. Better bitrate, meaning better overall quality.

3. Buttery smooth motion in regular speed.

4. You're not tempted to overuse slow mo and speed ramps.
 
13772019:plorr said:
Evan's (mostly) wrong. If you want really smooth motion in regular speed at 24fps, you have to just shoot 24fps. Although I do agree that smoother camera movement will help a lot to make the choppiness less apparent.

Dropping 60fps footage into a 24fps timeline will always result in that choppy look to some degree, because you are essentially no longer following the 180 degree shutter angle rule. Think about it: if you shoot 60fps at 1/125 shutter, then drop 60% of the frames to play it back at 24fps, it's the exact same thing as shooting 24fps with a 70 degree shutter.

Also, the a7s doesn't have the best motion cadence to begin with. Can't completely explain why, but some cameras are just worse at rendering motion in a pleasing way. Stept shoots RED which obviously has way nicer looking motion than an a7s. It can also be affected by which codec you use. With the a7s, don't bother with anything except XAVC. MP4 and AVCHD are absolute shite compared to XAVC. I noticed your clips are .MP4 so that could be a big part of your problem.

My advice to you: try shooting mainly in 24fps and 1/50 shutter, and a select few shots in 60fps that you know you'll want to have in slow mo. There's a lot of advantages:

1. You gain 1 1/3 stops of light, which is great for you because you're filming at night.

2. Better bitrate, meaning better overall quality.

3. Buttery smooth motion in regular speed.

4. You're not tempted to overuse slow mo and speed ramps.
Click to expand...

Although what you are saying is right, its getting a bit complicated for just filming skiing.

Every edit I've made in the last 4-5 years has been a 60p timeline exported to 24p. I rarely follow the 180 degree shutter rule, usually always a little higher. Maybe my video look isn't what OP wants, if you follow the shutter rules you can get that more "blurry" look you want.

The biggest issue with OPs footage is that it was shakey, anything at 24p will look more shakey because you have less frames to buff out the motion. IMO you should never film skiing at 24fps unless you really know what youre doing and understand how your footage will look.

My best advice to anyone just filming skiing and trying to establish a certain style is just to guess and check, try something new, if you like it keep going if not move on. Filming action is so much different than filming anything else, most rules people follow are random guidelines for filming narrative work, there are not a ton of resources out there for filming action.

Mess around with settings, try different things until you achieve the style you want, reading articles about how to make your video more filmatic won't take you very far, analysing numbers for your fps, shutter, export etc wont get you very far. Just go shoot!
 
13773849:eheath said:
Just go shoot!
Click to expand...

Yeah, pretty much. Just shooting and making edits is the only way to really figure out what settings and style of shooting work for you.

I work on a lot of narrative stuff in the off season, so I tend to notice stuff like sharp shutters in ski edits more than most, and it bothers me. So I avoid it in my own work. But for 95% of people watching skiing they won't notice or be bothered by stuff like that unless its SUPER obvious. The most important things are for your shots to be stable and composed/exposed well, and for the skiing to actually be good.
 
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