Jittery picture on slow-motion pan

Jessariah67 wrote on 10/19/2002, 5:09 PM
I have a crowd scene that I've slowed down to about 37%. The clip pans, and the picture is "jittery" when it plays back on a TV. The rendered avi plays back fine on screen, but once it goes to VHS, it jumps around a lot. Is this just the way it is, or am I missing something?

Thanks

Comments

mlane2 wrote on 10/19/2002, 7:33 PM
Do a search in this forum or search sonic foundry's knowledge base. There is extensive information out there on this subject. Simply put, the problem is when you slow down such a clip to a drastic 37%, there are not enough frames for vegas to use to give you the smooth playback you want. A few things to try: Use the "resample" option. Right click on your video clip then go to properties. Make sure to check the box next to 'resample'. What vegas does when you render is interpolate the frames. Vegas interpolates to 'make' the frames you dont have.

This works for most clips. The problem is if people in your crowd scene move fast, or you have slowed it down too much, you may still see some 'jittering'. You may also see slight 'ghost' images to anything moving fast.

If you do this and still see an unacceptable problem, I would suggest arranging your video so you dont need to slow down your clip to 37%. If you can run it a little faster and do the 'resample', you will probably see a better result.
Jessariah67 wrote on 10/20/2002, 4:15 AM
Thanks for the info. I'll do some digging and give your suggestion a try.
fuzzzzy wrote on 10/20/2002, 12:24 PM
Hi,
SF need to look at this for their next release as it is not a problem with AVID or Adobe premier.

I have tried all the settings suggested in this forum and the fact remains a very slow-mo WILL BE jittery and if you use resample you will get gohsting..period.

Best suggestion i would recommend is to re-record the particular scene with your camera set on slow-mo playback and insert the slow-mo recorded clip in your time-line during editing.

fuzzzzy
DGates wrote on 10/20/2002, 2:37 PM
I deinterlace, which seems to help.
BillyBoy wrote on 10/20/2002, 4:45 PM
I use slow motion a lot and it always is smooth playback.

a. avoiding getting carried away like trying for 1/10th normal speed.
b. remember to resample.
c. best results IF you break into smaller events and work each seperately.
Jessariah67 wrote on 10/20/2002, 5:26 PM
I took the velocity from 37% to 44% and resampled and it came out fine. This was jsut crowd panning at a football game -- if it was more cinematic or HAD TO BE slower, I might have hit a snag, but the above suggestions made a dramatic improvement. Thanks.
kkolbo wrote on 10/20/2002, 10:04 PM
I find that if I slow it down a little and then with resample and render to new track and slow it down a second time to get it where I want I get better results.

K
BillyBoy wrote on 10/20/2002, 10:34 PM
Try this:

Do not use an envelope. Instead, isolate the scene you want to slow down making it a seperate event. Stretch this event out by holding down the Ctrl key as you drag the event right while holding down the left mouse key. You should see a zig zag line that widens as you drag. Right click, switches, resample. You can adjust the event length to get the slow motion you wish.