Proper Chroma Keying

[Jack Pfeiffer]

Hi...

There's tons of help available on Keying... You just have to know where to look for it !
:bounce:

Here's a few on keying....

Keying with DV Video: http://www.fxguide.com/fxtips-223.html

Tips / Tricks on Keying... http://www.fxguide.com/fxtips-171.html

Complete Summary List of Tips, Tricks, Tuts, help and more:
http://www.fxguide.com/fxtips-201.html


bye,

jack
denmark

[Jack Pfeiffer]

Here's some more info for you all.........

The reason keying with DV source footage is always a problem has to do with how the DV codec compresses the signal infomation.. most importantly, the Chroma infomation.....

Read this link for a better DV-KEY technical explanation:
http://www.sundancemediagroup.com/tutorials/ChromaDV.htm

Here's a good DVC background info page from Expert Adanm Wilt:
http://www.adamwilt.com/DV-FAQ-tech.html (http://www.adamwilt.com/DV-FAQ-tech.html)

More good info here:
http://www.philipwilliams.com/greenscreen.aspx (http://www.philipwilliams.com/greenscreen.aspx)

You can consider buying the popular DVMatte Plug-In to help you pull a fast key (click to read more background info and learn....)
http://www.padd.com/market/product/product.php?prod=dvmatteae&sub=features

Next, here is a free "Combustion Tip" to pulling better DV keys:
How to prepare DV footage for keying:
1. Import your DV footage into Combustion. (Or capture it via DV if you have Combustion 3).
2. Apply a 4-pixel Unconstrained Gaussian Blur to the green or bluescreen layer.
Operators > Blur/Sharpen > Gaussian Blur.
3. Select the green/blue screen layer and apply Operators > Channel > Compound HSV Arithmetic.
4. In the Compound HSV Arithmetic controls, click on V layer and choose the footage from your original layer from the dialog box that appears.
5. For V Operator choose "Set". For V Input choose "Value".
After following the above steps, you should be able to pull a good matte.

Lastly, here's some general hot tips on keying:
http://www.fxguide.com/fxtips-171.html (http://www.fxguide.com/fxtips-171.html)
http://www.fxguide.com/fxtips-223.html (http://www.fxguide.com/fxtips-223.html)

Bye,
jack
denmark

[arlen]

wow it is a really helpful tip

[RelaxoRy]

I understand how to key and all that, but I was after more of a walkthrough using combustion which uses multiple passes to key specific areas. I use Digi Beta SP footage so the keys are usually quite good. But just recently I had a finance ad where the guy had a yellow shirt on and the girl was particularly blonde. The lighting was not set up properly in the studio and rather than re-shoot, it was left to me (and with good reason ;)).
Eventually, at 3am,
Rather than waste a long time with multiple passes which I didnt FULLY understand (I understand how (with multiple selections), just not much more), I got the boss to buy Ultramatte. With one circle and a click of Roto, my key was done. Then it was just a matter of waiting for 3 hours for 3 minutes of footage for the render (in Final Cut).

They key is brilliant, but it overkeys and leaves dust/specs in places - usually dark areas lit up by studio lamps. Multiple passes would be ideal in combination with Ultramatte, as it was hard to get entirely everything. It did the job though, and is very good on fine details which I never thought was actually possible. I'd post a screenshot of what I was working with, but it'd mean digging out the footage again and I hate the job with a passion :)

Ciao Ciao

[CGTalk Moderation]

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.