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Peckhammer

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I shot some footage on my AH-A1 last night. In reviewing the footage, I notice that all the pans look a little choppy -- a kind of stuttering almost. The camera is set to shoot 24F, shutter speed was 60fps. Any ideas?

I am wondering if there is anything that can be done to smooth out the motion in post, using Premiere. Frame blend? Or maybe 24F needs to be interpreted? Any tips, thought or suggestions would be appreciated.

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Peckhammer
 
Hi Peckhammer,

24f mode is cannon's 24p. Did you mean to shoot in 24p? It is by nature more stuttery than 30p, 60p or 60i. When shooting 24p, typical settings for shutter speed should be 1/48th (and reduced as low as 1/24th for more motion blur). Having a shutter speed above 1/48 will increase the choppiness of the look (think saving private ryan or a zombie film). In the case of your post, it seems you shot with a shutter speed of 1/60 second.

Not sure about the post question, I don't work with 24f anymore. it is likely that 24f is 24 frames per second built into a 60i (29.97 timecode). Possibly removal of a pulldown might make a difference?? It is most likely that re-shooting or living with it will be the only real alternatives.

BTW - shutter speed is never expressed in fps (frames per second). It is expressed in fractions of a second (1/48) or degrees in a circle (180 degrees).


Jason
 
Jason,

Thanks for the reply. Yeah, I was intending to shoot 24p. I have noticed the same thing shooting 30p, but not 60i. The most important thing you said, for me, was using 1/48th shutter speed. And yeah, not fps. I know better, but I don't aways articulate it very well.

The post question is simply whether or not there is something to be done in post production to smooth out the jerkiness. I thought that something that blended frame transitions might work. Seems that the real answer is to just capture better footage by using the right settings.
 
Yuppers. No OIS if on a tripod or using a 35mm adaptor.

Generally, 'fixing it in post' is bad news. There might be a fix that I am not aware of, such as frame blending, but not matter what the problem (lighting, contrast, focus, audio, blur, grain, resolution, poor hand held footage...etc), it is never a good idea to leave it to post. I realize you are simply wanting to fix something that didn't go as planned, hopefully there is a solution that someone else can being to the table (in fact, if you figure something out, share it with us). The teachable moment here is, fix everything you can while shooting. Its much easier and sometimes the only possibility for clean audio and video.

Best wishes on manipulating your footage.


Jason
 
AwakenedFilms said:
The teachable moment here is, fix everything you can while shooting.
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Yeah, for sure. The footage is usable for internet video, just not perfect. I ran some tests this morning, shooting footage at 24F and 30F, and trying 1/48th and 1/30th shutter speeds for both. I still see the stuttering, although it is a little better at 1/30th despite the noticable blur. Maybe "quartz-like" movement is just the nature of this camera -- or maybe my 501 HDV tripod head is junk.

I've put together 1.5 minutes of footage from my test shoot the other night to illustrate what I've been talking about. Most shots are done on a tripod; a few are handheld, and OIS was off for the entire time. The pans and tilts are where you'll notice the most stuttering.

http://www.vimeo.com/11400641
 
That stuttering or jerkiness is unusual. Does it stutter when you play it back on the camera and view on the LCD? If so, the tension on the tape may be a problem. Try a different tape.
 
jleo said:
That stuttering or jerkiness is unusual. Does it stutter when you play it back on the camera and view on the LCD? If so, the tension on the tape may be a problem. Try a different tape.
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Thanks for your comments. Watching the footage back on the camera's LCD fiip-out monitor, it looks fine. I just hooked the camera to a Mac, started iMovie, and captured the footage in iMovie and watched it back, and it very clearly stutters.

I shot more footage last night, with a different tape. I moved super slowly, using a dolly as well as a very expensive tripod head (i.e., smooth). Even with crawling pans, the stutter is still there. Here is an update sample of from my guitar documentary test shots, which has footage from two different tapes: http://www.youtube.com/watch?v=QvPWc0np9bY

On my PC, using the source monitor in CS4 to look at the captured clips, I see the stutter on EVERY motion shot. All static shots look fine.

--> Update: I just went to a camera store, and shot dolly footage with an A1 right out of their showcase. I used the same camera settings (with the exeption of my Allister Chapman AVG FILM preset), imported the footage to their FCP mac and watched it back. It looks smooth as silk. So it's gotta be the camera, a codec, or Chapman's preset (which I doubt).
 
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You are using CCD, so rolling shutter is not affecting it.

24 has slightly more stuttering than 30p. But it will look ok on a true 24p display. But LCD computer monitors are 60hz so they do not display 24p material properly. I believe that's what you are seeing. If you have a CRT computer monitor that can do 72hz, it will look ok on that. If you burn media and play on a true 24p display it will also be ok.

It could be that the editor is not handling 24p on 60i properly with your settings. Try shooting a fast chronometer or a record turntable at a fast shutter and stepping though frame by frame on the timeline. If you see equal radial motion from step to step, the problem is your 60hz LCD display. If it jumps, the problem is the editor configuration.

A quick check is to output video and change its frame rate so that it will play at 30p. Make sure there is no frame interpolation applied. If the stuttering is gone, the problem is the 60hz computer display.

EDIT. You say you notice the same thing when shooting 30p. So the problem is not the equipment. You just don't like panning and motion at normal frame rates:) Do 60i. There are some 60p cameras around and they make some TVs now that are 240hz which interpolate anything to video game smoothness.
 
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Ok, I checked the footage by downloading the vimeo file and stepping through in quicktime player.

There are two problems:

1) The footage is not correct so the editor is not setup properly. The pan at 1:18 shows the problem. Quicktime shows a 29.97fps video file.

The frames are: 1 1 2 3 4 5 5 6 7 8 9 9 etc. The two 1s show the same panning moment but slightly different. And this is repeated in the two 5s etc. Your 4 frames are converted to 5 frames. Your 24p became a 30p file by a duplicate frame. This should be easy to fix by changing settings.

2) Even if that problem did not exist, the LCDs are 60hz so 24p will still stutter on a pc display. But not the 100% frame duration stutter you are getting now with those 5 duplicate frames every second. It will not be that bad.
 
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Otis Grapsas said:
Ok, I checked the footage by downloading the vimeo file and stepping through in quicktime player.

The frames are: 1 1 2 3 4 5 5 6 7 8 9 9 etc. The two 1s show the same panning moment but slightly different. And this is repeated in the two 5s etc. Your 4 frames are converted to 5 frames. Your 24p became a 30p file by a duplicate frame. This should be easy to fix by changing settings.
Click to expand...

Bingo! I see that now. Of course, I changed so many things in trying to troubleshoot this that I got lost. I updated Premiere, and figured out that mixing 24F and 30F in the same sequence was not a great idea. See, I had dragged the 24F clips to a 30F sequence; there is both 24F and 30F footage on that timeline.

My remaining question is how to handle a single project that has both 24F and 30F footage? My guess for how to use 24F and 30F footage in the same timeline would be to actually drag the 24F sequence -- not the clips, but the actual sequence -- into the 30F sequence. Is this correct?

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Peckhammer
 
In a mixed project, go for the output you need the most which boils down to the % of each frame rate. I would shoot and edit everything 30P in USA, it looks excellent on computer and tvs. For europe it's harder to choose, 25p looks good on tvs and 30p looks good on computers.
 
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