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-   -   Keying with vegas (http://www.dvinfo.net/forum/what-happens-vegas/63910-keying-vegas.html)

Jim Rog March 29th, 2006 03:14 AM

Keying with vegas
 
Hello

Does anyone know any other keyer other then the standard one in vegas? cant seem to find any info on it but can primatte 3 work with vegas or only after effects? i am after a add on or plug-in that is going to give me a better key with green then the standard one

Thanks for your time

David Jimerson March 29th, 2006 06:22 AM

What problems are you having? Vegas keys brilliantly with green.

Robert Kirkpatrick March 29th, 2006 08:26 AM

Quote:

Originally Posted by David Jimerson
Vegas keys brilliantly with green.

And on a curious tangent, does Vegas key well with blue or any other color? (I'm working with a green costume for my next shoot.)

David Jimerson March 29th, 2006 09:54 AM

It'll key any color (or range) you specify.

Working with DV, blue is sometimes problematic, because the blue channel can be noisier than the others.

Seth Bloombaum March 29th, 2006 11:07 AM

I'm still looking for a project to justify purchase, but *many* people have reported great results with Serious Magic Ultra 2 for green-screen with DV. seriousmagic.com.

There's a forum here covering Ultra and DVRack (also an SM product).

Douglas Spotted Eagle March 29th, 2006 11:19 AM

I'm a major fan of Ultra 2 for speed, but I can achieve nearly as good a key with Vegas in *most* cases, but it takes more time.
With Ultra, or Vegas, you can key from any color, but red specifically is the most difficult key in DV, due to the way DV samples. You can easily use lighter blues, but as David mentions, blues, or specifically deeper hues, can cause a problem. This is due to how DV samples. Luma value is the key factor in any color.

Jim Rog March 29th, 2006 12:01 PM

Hello

Its HD i am keying with just posted in wrong topic

Any how when i try to key the green out its taking some of the subject out with it the screen isnít lit as best as it could be but i donít have a lot to work with it does ok but then when i want to insert another back ground over it you can still see some of the green. is there any way of brightening up the background without touching the subject so it makes it easier to key?

Thanks again

David Jimerson March 29th, 2006 12:16 PM

You've got sliders in the key editor. Try bringing the low up and the high down.

Also, you can use the secondary color corrector to saturate the green and only the green -- apply that before you apply the chroma keyer.

Phil Hamilton April 17th, 2006 09:01 AM

Cleaning up the edges
 
I am having pretty good results keying out an object with fine lines against a blue background. Both are computer generated. I am using Chroma Blur, Secondary Color to saturate the blue since it is a "sky" and some unevenness is there, and then finally the Chroma Key.

But now I have a fine blue finge/noise around the object. I went to this forum
http://www.dvinfo.net/conf/showthrea...roma+secondary

The suggestion there is to put the Secondary Plug in AFTER the Key plugin. Can someone explain the difference in what is being done here? I thought you would need the secondary CC before the key so you could get a great key. Thoughts? Things look good except that pesky blue noise.....

David Jimerson April 17th, 2006 09:40 AM

No, you need to correct the keyed color before you try the key, so put the corrector in before.

Also, adding a chroma blur between them may help some.

What's being suggested in that thread is to use a secondary corrector for post-key cleanup. You apply it only to the keyed image to try to mitigate the spill. You wouldn't be making the blue more blue; you'd try to get rid of it entirely.

Douglas Spotted Eagle April 17th, 2006 09:45 AM

Quote:

Originally Posted by Phil Hamilton
I am having pretty good results keying out an object with fine lines against a blue background. Both are computer generated. I am using Chroma Blur, Secondary Color to saturate the blue since it is a "sky" and some unevenness is there, and then finally the Chroma Key.

The suggestion there is to put the Secondary Plug in AFTER the Key plugin. Can someone explain the difference in what is being done here? I thought you would need the secondary CC before the key so you could get a great key. Thoughts? Things look good except that pesky blue noise.....

Phil,
the order in which you want to do this is:
1. Secondary color corrector to even out the blue
2. Chromablur set to a value of 2.0 (assuming DV source)
3. Chromakey tool
4. Any color correction for the subject in the key itself.

Phil Hamilton April 17th, 2006 10:46 AM

Quote:

Originally Posted by Douglas Spotted Eagle
Phil,
the order in which you want to do this is:

4. Any color correction for the subject in the key itself.

So at this point for step 4 would I use the regular color correction or another secondary color correction to touch up any remaining blue? tks for your quick responses...

Douglas Spotted Eagle April 17th, 2006 10:50 AM

No. Step 4 is for correcting the SUBJECT within the image. If it comes post-key, it won't affect the blue at all.
Did you shoot blue with a DV source? If so, you're likely going to need to create a garbage matte. Blue isn't a good option for DV sourced-material. You really needed to use green, for the substantially higher luma value.
To create a garbage matte, I have a tutorial at:
http://www.vasst.com/resource.aspx?i...f-b305852df8a7

Phil Hamilton April 17th, 2006 11:28 AM

Great tutorial - an easy way of creating a travelling matte. I will give this a try.

I do have another question regarding masking out areas to be keyed. I have this object and I use the Bezier tool to mask around it leaving a little of the blue area to be keyed out. When the object is against a lighter background I can make out the edges of the area I've masked out! This does not seem to happen with cookie-cutter but the bezier tool is great for creating a custom shape.

What is better to use - the bezier tool or cookie cutter? And when using the bezier tool is it generally better to feather - in - out - or both to clean out the mask line?

Douglas Spotted Eagle April 17th, 2006 11:37 AM

Quote:

Originally Posted by Phil Hamilton
What is better to use - the bezier tool or cookie cutter? And when using the bezier tool is it generally better to feather - in - out - or both to clean out the mask line?

There is no "rule." You'll find it's entirely project-dependent. I use both, but end up using Bezier most of the time, and feathering is often "both."
HTH


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