Fusion Quick Tips: Color Correction Node Alpha Issues

Hello and what is going on i'm mal director. This is el director vision and you're, watching indie rebel hollywood effects without the hollywood budget. Today. What i want to do is give you guys just a little ldracker, quick tip on using the color correction node here inside of fusion in davinci resolve. You can see we're working with resolve 17 studio version uh. This will work in the free version. This also works in the standalone version. I want to show you guys a problem you might run into when using the color corrector on your keyed green screen footage. So let's go ahead and add the color corrector here into the flow, and we can see our panel pops up over here and uh. Let'S just say i want to you know play with the saturation. You know kind of make that look good. Let'S go into the mid-tones screw with that, a little bit more yeah, nice and poppy there. We go right. This obviously is not color matched, but you'll get the idea with what i'm about to show you so maybe, for whatever reason i want to start screwing with my contrast, i don't like the way this looks. I could come in and play with the gain. You know. I could do it that way, or maybe i'm lazy, i'm just going to use the contrast, slider, oh, what is going on you can see like it's affecting the whole image. Why is that? This is a problem you're gon na run into, and the answer has to deal with something called pre-multiplication of your alpha channels and that's just a fancy way of saying that there's a switch that needs to be checked. So let's say i wanted to. You know increase the contrast of just her, not the background. Here'S how you fix it come on over to your options, page our panel here in the color corrector and just hit the switch it's all you got to do and now it goes back to normal. Now it's working the way you would expect it to i'm only color correcting the girl, as i start playing with the contrast, because at first you're thinking hey in after effects, i would come in. You know and key my shot. Just like this um. You know, and now i can start doing my color correction to it and it's it's looking good here. If we uncheck the switch, it's still looking good uh, but why is it looking horrible down here and if we look at our hair we can actually see a little bit of the giveaway here with it. If i come in and hit the switch, we can see that our edges are suddenly being improved and that all the alphas are responding. The way they're supposed to there's a lot of transparency here in her hair and that's why we're seeing it? Finally, now here on, just the alpha background, so if we go back to our final shot and zoom back out and let's just go ahead and fit this thing to fill, if you're, finding yourself struggling with your color correction and things are not responding, the way you Want it to head on over to the options page and make sure this uh pre-divide slash, post multiply box is checked if you want to see more quick tips like this go ahead like and comment and uh don't forget to hit that subscribe button as well. We'Ve got plenty more along the way, i'm l director - this is l, director, vision and you've been watching indie rebel hollywood fx without the hollywood budget.