Colour changes

[Adam Stanislav]

Originally Posted by Chris Barcellos

I notice he goes to brightness and contrast as his first correction. I like to go right to Levels, which I think give you more control over adjustment.

I had the impression he wanted to start at the bottom, with a very simple quickie tool, then build up to better and more powerful tools. And since he works for Sony, he probably did not want to imply that any of their tools might not be useful. :)

I wonder why it always takes them weeks to post the archived webinars. It took me a couple of hours to make my own MP4 from my recording. And it only took me so long because Vegas could not read the audio from the MXF format, so I had to first export the sound to WAV files, and then Vegas took two and a half hours to render it. I have just finished watching it the second time.

[Renton Maclachlan]

Originally Posted by Eric Olson

As a note for the future, automatic white balance is dangerous for green screen and worse for blue screen.

Why is that?

[Gerald Webb]

Originally Posted by Adam Stanislav

I wonder why it always takes them weeks to post the archived webinars. It took me a couple of hours to make my own MP4 from my recording. And it only took me so long because Vegas could not read the audio from the MXF format, so I had to first export the sound to WAV files, and then Vegas took two and a half hours to render it. I have just finished watching it the second time.

Wouldnt be putting it up anywhere would you Adam?
"Cough,"
https://www.yousendit.com/

[Adam Stanislav]

Originally Posted by Gerald Webb

Wouldnt be putting it up anywhere would you Adam?

That is why I was asking about their policy. I would not want to violate Sony’s copyright.

[Seth Bloombaum]

Originally Posted by Eric Olson

As a note for the future, automatic white balance is dangerous for green screen and worse for blue screen.

Originally Posted by Renton Maclachlan

Why is that?

Because in automatic, a camera's white balance changes. Cams vary in how much of the image they sample for auto WB, to include as much as the whole image.

If the white balance changes when people move, or walk out, or walk in, or turn their head, the color of green in the recording is going to change with the WB. Which makes the key inconsistent... which can lead to lots of "fix it in post" that takes many extra hours and likely won't be of the quality one could achieve more easily with better shooting.

[David Jimerson]

I tend to hit the curves first.

[Adam Stanislav]

I generally hit the three color wheels first, then adjust with the curves.

[Renton Maclachlan]

Originally Posted by Seth Bloombaum

Because in automatic, a camera's white balance changes. Cams vary in how much of the image they sample for auto WB, to include as much as the whole image.

If the white balance changes when people move, or walk out, or walk in, or turn their head, the color of green in the recording is going to change with the WB. Which makes the key inconsistent... which can lead to lots of "fix it in post" that takes many extra hours and likely won't be of the quality one could achieve more easily with better shooting.

I've had the WB shift on another shoot - because a lady picked up a sheet of white paper and waved it around while she spoke. In my present shooting - with me as the presenter - I'm pretty static so there is little to no change.

Never the less I agree - I should lock the WB down as well...

[Renton Maclachlan]

We'll I've been playing around with the colour changes in my clips using the colour corrector and curves, and even though I say so myself, have got things pretty good.

Thanks Peter for the link to the Webinar. I down loaded it and went through it. Good stuff.
Used the three colour wheels first - lows > highs > mids, then curves. Didn't use the Brightness and Contrast - didn't need to...

The last bit of filming I did - I have about 10 more like this to do - I manual'ed the WB which had one shot really good so used that as my standard for all the others, something like 22 in all. By the time I got to the last one I had it down to a fine art...

David Jimerson said: "And if this is going to be chromakey footage, I'd work on the color matching *after* you pull the key."

Why would you do this? Because the green could throw the eye out when doing the colour correction?

I'm going to be adding a lot of of other stuff to the time line eventually, which I imagine will slow the computer down considerable. Would it be advisable to render out the colour correction so that that is not having to be done, along with everything else, in the later part of the post production?

If I was to do this, would it be best to 'pull the key' - without putting the replacement image in place - before rendering?

I would like to remove as much that consumes computing power as possible, before I start adding all the other stuff to these basic clips.

RE quality of key. Obviously I'm wanting my key to be as good a possible (doesn't everyone?). Originally I was thinking of putting a light background behind, however it seems light backgrounds will accentuate any residual green fringe so that may not be a good idea. If the background image can reduce attention to any fringe that would be good. Any thoughts on this question of backgrounds minimising 'fringe'?

[Adam Stanislav]

Originally Posted by Renton Maclachlan

Because the green could throw the eye out when doing the colour correction?

<... snip ...>

Originally I was thinking of putting a light background behind, however it seems light backgrounds will accentuate any residual green fringe so that may not be a good idea.

Regarding the first question, most likely the opposite: Because color grading might throw the key.

Regarding backgrounds, if lighting the backs of your actors does not separate them enough from the green reflecting from the background, increase their distance from the screen. If you cannot or if that is not enough, light their backs with just a bit of magenta light. Magenta is the complementary color to green, so they cancel each other. Of course, you need to do that while producing the footage, not while you’re editing it.