Pan & crop jittering

J

John C.

Member
I'm working on a new project using mostly stills. When I do slow pan & crop, the image jitters (I mean it doesn't move smoothly). When I render to a m2t file all is perfect, but when I render to mpeg2 for a DVD the problem occurs. The same is true with the rollover credit titles in the end of the film. Any suggestions?
Thanks
 
I'm rephrasing my previous question in case anybody can help: I work mostly with stills. When I do pan and crop, or when I add rollover titles, both of which involve movement on a picture, the movement is not smooth (both on the timeline and in the final rendered file). To give you an idea, it seems as if it needed more fps. When I render to an m2t file everything is perfect, but since I need to burn DVDs, I need an mpeg file.
If anybody can think of any solution I would appreciate it very much, as my projects are composed mostly (more than 90%) of stills.
 
What's a m2t file? Never heard of it. The only time I've had concern with photos looking jittery in a rendered DVD was when I was doing it in a 24P timeline/project.

So the bigger question is what are your project settings and what size files/photos are you working with?

To overcome this in 24P, you'll need to use some motion blur through your video bus ... perhaps some super sampling as well, you'll have to play with it & see what delivers the best results for you. Keep in mind, render times will be SUBSTANTIALLY increased with motion blur & supersampling.

The reason why photos want to flicker/jitter when panning in 24P (assuming that might be your issue) is the same reason why video flickers when you're panning your camera in 24P mode. Barry Green posted once that to get a TRUE non-flicker with 24P while panning, you need to take approx. 2 minutes to just make a 90 degree pan. Insanely long, but that's the standard as set by film pros (some association/group I can't recall the name of). So I imagine that you'd want to apply the same math to your still photos if panning in a 24P project.
 
You need to tell image to always deinterlace... it should get rid of the jitter... also something else you might want to try is outputting to tape, and seeing if it displays the jitter on your TV. Sometimes composite shots with images like that only jitter on PC... it's a refresh rate thing, I think.
 
Good point. He never mentioned that he had actually made it as far as a rendered DVD, just that the MPEG2 jitters .... which could be because he's playing it back through the PC.
 
Envision said:
What's a m2t file? Never heard of it.
Click to expand...
MPEG-2 Transport Stream file. It's the native file format used by HDV camcorders.

Barry Green posted once that to get a TRUE non-flicker with 24P while panning, you need to take approx. 2 minutes to just make a 90 degree pan. Insanely long, but that's the standard as set by film pros (some association/group I can't recall the name of).
Click to expand...
That's from the American Society of Cinematographers. However, the time depends on the focal length you're using. The more telephoto, the longer the pan would need to take. The wider-angle, the quicker you can pan and have it still be smooth. For a 90-degree pan at 100% telephoto, yes, about two minutes. At 100% wide-angle, the same pan can be executed in 15 seconds and still be glass-smooth and jitter-free.
 
Some more information:
The stills are taken with my Canon 6 mpixel and 8 mpixel cameras (3072x2048). I don't want to reduce their size as I want to be able to pan and crop them.
The jitter appears not only on my PC but also on DVD.
Until recently I had a flickering problem too, which I solved by selecting "progressive" instead of "interlaced"

dj200423: how "to tell image to always deinterlace"? If you mean the "reduce interlace flicker" switch, I see that it has limited capabilities. Can you please explain?
 
John C. are you editing this in a 24P timeline? If so, see the above comments to help reduce/eliminate that.

Otherwise, if you're rendering out to a DVD that is only at 720x480 max, I'd seriously consider resizing those images so that they're maybe three times 720x480 res at the most. Unless you really need to zoom WAY into the picture for a specific reason, those files are probably much larger than you need.

When I have clients that want me to work with still pictures, I simply request that they give them to me at at least 1440x960. That way, I can zoom in by about 2x, and still have everything perfectly sharp, and it gives me a ton of room still to add some dramatic flare to it, or emotion. The res. you're talking about is MASSIVE.
 
The jittering you see is aliasing artifacts. You need to use "sub pixel rendering" in Vegas to get rid of this. I posted detailed instructions here a few months ago -- try searching this forum.

It works very well, however expect rending time to become ridiculous. Fortunately, you can use curves to add this procedure only where the problems occur.

I use many hi-res picture pan-and-scan in docs and corporate work and it looks very elegant. A digital camera now goes on all shoots, and I end up with several hundred pics per job -- which makes it sooooo much easier when editing.

The good thing about using pictures is that you can do a very slow crawl zoom or pan across whatever you're talking about, so you don't really need to know what the exact narration will be while shooting -- only that something in this picture frame is important. The bad thing is that you have to make sure that there's no movement in the frame (people, vehicles moving, moving steam, water, or smoke) or it'll destroy the illusion that it's video (though it's a good effect for illustrating "historical" footage, especially if you tint it.)
 
You must log in or register to reply here.
Back
Top