Video Apex Bookshelf

Saturday, October 4, 2008

Exposure Control

Often during simple compositing operations, we find something that looks good on our monitor, but as soon as it's shown on film or certain television sets, the composite no longer holds together. Take this following example:

We have this nice background plate footage here:

And this garbage-masked green-screen footage ready to be keyed here:
So we pull the key with Keylight, and this is what we get:
Now obviously it's too bright and there is not enough contrast in the above image, so we add a grayscale adjustment layer, and play around with the keyed shot until we have something that we think looks good, like this:
Unfortunately, those shadows would pull apart from the background when displayed on many TV monitors, such as the one I have connected to my workstation. A great but little known tool for just this is called Exposure Control. As of CS3 you don't have to be in 32bpc in order to take advantage of it. It's located in the bottom right hand corner of the comp window, and is very useful in performing a slightly modified version of 'gamma slamming.' When we crank up the exposure, we can see that the shadows on his black shorts are much too bright compared to the black rails in the background, or even the shadows on the ground in the corner:

So now we can do some further adjustments, and notice that the shadows of the shorts match much more closely with the background than before, and they have a nice fade-off into the lighter shades, just as the darks on the floor do:The final composite (of just the shadows) can be seen here. Obviously we still have the highlights, shadows, midtones, and color to worry about...but that's a different post.

9 comments:

Thomas said...

Thanks a lot! That helped will help me alot on those tricky shots, where there obviously are something wrong.
At last thanks for all the great tips you provide us with. It´s really helpfull.
Cheers

Mwdctnry said...

Thanks. I was reading somewhere before that to do something like this, you can create an adjustment layer, apply curves, and slam the gamma. Is there any particular reason for the difference in the two techniques?

Grant Swanson said...

No reason...it's just quicker and easier.

dudette said...

Awesome Thanks!

Mike said...

This has actually been a problem with me in the past...thanks.

Anonymous said...

killer tips dude!!!!!!!

Anonymous said...

I always thought that was for allowing you to see superbrights as a preview...but this is a unique way of using it I've never thought of before. Keep up the tips.

Anonymous said...

Greatly apprecieated.

Artist Rob said...

Grant, just wanted to give a shout out, you got some great stuff, hope to see more of your stuff on creative cow....