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Grading: How to match lighting from backdrop to foreground

Posted: Mon, 7th Aug 2006, 8:26pm

Post 1 of 3

Buu

Force: 1061 | Joined: 16th Oct 2004 | Posts: 33

CompositeLab Pro User EffectsLab Pro User FXpreset Maker Windows User

Gold Member

Rating: +2

Hi, this is my first post on FXhome so I’ll try to make it useful. This tutorial teaches matching real lighting from a background to your foreground. The steps are short and (hopefully) quite simple but it should help a few of you who are having trouble making their composites look believable. If you have no idea what I’m on about now the pictures below should help;
Before


After


Getting set up
To start I’ll just BRIEFLY explain how to use CompositeLab Pro to get a good key.
Make sure you import both (or more) of the files you want to have. Keep the background layer underneath the foreground.

I’d suggest a key grade and I find;
Brightness
Contrast
Saturation, works best.
You just need to adjust the settings for your own compositing. Remember to use chroma-key also.





Go over and turn grade mode on. Add a spill suppression at this point.
Make sure you have Project overview on, or else this would be very hard. Now select an Ambient light, click on the colour picker and drag it over the object closest to white in the background. You may need to turn off the foreground to see the whole backplate. The reason we’re doing this is, the white will be tinted in the key light colour, in this case the key light is the sun. It’s important to find an object in direct light in your backplate which is close to white as this will give you the correct colour for your ambient light.



Use Lightness HLS to brighten your foreground, making sure that the darkest shadow in the foreground element is no darker than the darkest shadow in the background.



I added a second ambient light with a more intense colour at this point and increased its “intensity” to what looked okay. Don’t go for too much here, it may be worth taking a break and coming back to see if it is. You don’t want to end up with orange people about, unless it’s a “Charlie and the Chocolate factory,” film. Now you have done that and things look okay to you we can add the finishing touches.




I added a light spill and increased its “strength” on the image, to 41, you may not need one. Well that’s pretty much it, just remember if you have a strong light directly in the background always you’re your foreground darker, if it suits. These are some things I have picked up myself from other tutorials but adapted to make it suitable for CompositeLab Pro, rather than a 3d app. Hope this has helped!
Posted: Mon, 14th Aug 2006, 11:42am

Post 2 of 3

metalfish

Force: 600 | Joined: 30th Apr 2005 | Posts: 3

CompositeLab Pro User

Gold Member

Quite usable Basic Lightmatching Tutorial... thanks! Really useful..
Posted: Thu, 17th Aug 2006, 7:28pm

Post 3 of 3

Jazzmanian

Force: 765 | Joined: 3rd May 2006 | Posts: 719

CompositeLab Pro User Windows User

Gold Member

Excellent. Well explained and useful to anyone just delving into the world of compositing. Nice job.