View Full Version : need advice on this clip...


Jerry Neal
November 29th, 2011, 09:35 PM
Hello,

I'm trying to use the "compositing" mode in Vegas for the first time. My goal is to combine or "overlay" the horse footage with the dog footage. What I don't understand is why the jump appears to be in front of the dog and horse, even though both animals jumped over this obstacle. Also, the camera position and jump was not moved during each scene, so the framing and position of the jump did not change..

If anyone has any suggestions to improve/achieve the look I'm trying to get, I'd appreciate your input. Again, just trying to have the dog and horse appear together in the same scene by combining these two clips.

Untitled on Vimeo

Thanks,

Jerry

Graham Bernard
November 29th, 2011, 11:44 PM
Jerry, that is truly odd!!

A] Camera angles haven't changed - the back and side walls confirm this.

B] The floor dirt hasn't moved nor the corners of the shed.

C] I can't detect any WA change

So what's left? What elements are in that footage? The animals, the "jump" and the horse reign.

Well, and on very very close inspection the angles of the actual jump are different in each shot. Again, the angles, not the angular Track Motion alignment, but the heights and jump legs are different.

My opinion? I think that with the horse's weight or hitting the jump or even the tether, something may have adjusted the jump's position.

You could confirm or reject my idea by scrutinizing a still from each footage, or see if you can observe any gradual or sudden change in the jump's appearance.

If I'm correct I wouldn't know what to do, other than the unthinkable and re-shoot. Hopefully I'm wrong and there is a more reasonable Vegas-fix. I've thought of maybe a localised re-distort option - not nice . . . .

HTHs

Grazie

David Jimerson
November 30th, 2011, 12:07 AM
Just a guess, but I think it's because you have the clips to 50% opacity. Everything that doesn't move is thus effectively 50+50, or 100% opacity, but the moving objects -- the dog and the horse -- are only 50%.

Again, just a guess.

Graham Bernard
November 30th, 2011, 12:14 AM
Good point David. So, on that basis, maybe the Jump DID move?

G

Steve Game
November 30th, 2011, 01:59 AM
Did you have the AF switched on. All but the highest quality lens breathe when focus is adjusted.

As far as the bar appearing in front of the dog, that's because the bar in the horse clip is still visible at 50%. If you look carefully, the bar in the dog clip (which is slightly lower than in the horse one) does obscure the horse's legs, although this isn't as obvious as the leg colour is similar to the bar.

Steve

Gerald Webb
November 30th, 2011, 04:31 AM
Rather than worrying why, maybe adjust one of the shots to sync the 2 jumps into position,
Then as they come over the jump there is enough distance to have a mask in between (with a few pixels of fade) and use Source Alpha for each clip.
The leash on the horse could be masked out completely.
If you want to upload the source clips I'll give it a go, I'll have 1/2 hr to spare tomorrow.
:)

Mike Kujbida
November 30th, 2011, 05:34 AM
Jerry, see if the following tutorial on difference compositing helps at all.
Two cats from one (http://matthew.chaboud.com/vegas5/twocats/)