Chromakey & Multicamera editing – Works OK?

[John Rofrano]

[Alf Hanna] “I setup the shots correctly, but am having a hard time properly keying this dual camera setup. Are there any thoughts about this? Best practices? I’m almost of the belief, in just a short time of working on it, that it’s more effort than it’s worth. “

You want to chroma key the Media not the Events. (or Track!) Add the chroma key as a Media FX and then the multi-cam should cut together easily because the media is already keyed regardless of which event it is used in.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Al Bergstein]

Sorry John, email is not a precise communication tool. I did add the Chroma key to the media not the events or track, as you mention. And maybe my problem was that I was not keying *prior* to going into multicamera editing. I was editing then keying. That makes sense, I’ll try doing it as you suggest today.

So the method is:
1. insert the clip that you will key.
2. insert the second clip that you will key.
2a. remove the unwanted sound track from whichever track is worse.
3. Add the background (this could be done first of course).
4. Key clip 1 to the background.
5. Key clip 2 to the same background.
6. Enter multicamera editing mode.
7. make the cuts between the various takes as you see fit.

Does that seem to be correct?

Did I miss a video training program on keying that someone has done?

Alf

[John Rofrano]

It shouldn’t matter what order you do them in. What is the problem that you are seeing? I would imagine that keying two camera angles over the same background wouldn’t look correct to the eye. If the camera angle changes, the background should change with it.

What you might want to do is to key each video against the background first. Then render that to a new track and use the new tracks for multi-camera edit.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Mike Kujbida]

[John Rofrano] “I would imagine that keying two camera angles over the same background wouldn’t look correct to the eye. If the camera angle changes, the background should change with it.”

John is right.
I shot an interview last summer that I ended up chroma-keying using a generated media from Vegas as the background.
Any time I changed from the wide shot, I made sure to zoom in on the background as well.

I’m guessing this would be even trickier with two cameras so make sure your background(s) matches the foreground action.

[Al Bergstein]

Yes, I’m probably going to abandon the effort. Another problem I’m facing (other than the background angle which I forgot about until you mentioned it), was that when I shifted to Create Multicamera Track Vegas warns that it will strip out effects, etc. which is why I had the problem in the first place. It seems to be saying that my keying, white balance, etc. is going to be stripped out, and in fact that is what happens. So I think you are right in that I would have to render the footage first as a keyed footage for track one, then key and render the footage for track two, then create a multicamera track with the two of them. Way too much effort for what I’m getting paid, and I get an odd angle of looking at the background anyway. But I may try it for the learning experience at some later, less pressed, moment.

Would you two agree with that approach?

Alf

[John Rofrano]

[Alf Hanna] “It seems to be saying that my keying, white balance, etc. is going to be stripped out, and in fact that is what happens. “

I thought you said that you added the chroma key as a Media FX? If you did, this should not be happening. Media FX are not affected by multi-camera work.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Al Bergstein]

Ok, I’m out of the editing suite for a few days, but will retry this. It was my belief that the first time I had spent time applying the key and the color correction to clip 1 using media fx, then to clip 2 and then merged them using multicamera editing. But I’ll give it another try and see what happens when I get back. maybe there is something I missed. Thanks John, for helping me think through this.

Alf

[John Rofrano]

The only FX that are removed during multi-camera mode are Track FX because you are combining multiple tracks and the FX can’t be combined. Media FX and Event FX should not be affected by this merge, just Track FX.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Larry Cole]

I noticed that you indicated you were using Boris’s chromakey software. What is the advantage of using a add on vs. the chromakey effects built into Vegas? Is the quality significantly better that would justify the additional cost?

[John Rofrano]

[Larry Cole] “I noticed that you indicated you were using Boris’s chromakey software. What is the advantage of using a add on vs. the chromakey effects built into Vegas? Is the quality significantly better that would justify the additional cost?”

The Quality and Functionality is significantly better to more than justify the cost. The Sony chroma keyer has very minimal functionality. It doesn’t have any way to choke the matte. It doesn’t have any way to adjust the weight of the colors that it uses. It doesn’t have any spill suppression and it has no way to wrap the light from the background around the foreground subject. Boris Continuum Complete has all of these tools and because of this, they work in situations that the built-in chroma keyer cannot handle.

If you have perfect conditions with good even lighting and no spill, the Sony keyer will do a fine job. For all other keys, you really need something like BCC7’s Chroma Keyer.

~jr

http://www.johnrofrano.com
http://www.vasst.com