We all know how important lighting is in the process of shooting a subject against a green screen. However, having the ability to pull a solid key from any footage (whether it's well lit or not) is perhaps one of the most important skills for somebody to have in the world of post-production. This is especially important considering that many low-budget editors are now becoming the one man bands of the post-production process. Luckily, programs like Premiere Pro include a plethora of effects that can be used to pull a fantastic key every single time, and without the need to leave your NLE.
As is the case with many of the best Premiere Pro tutorials, these next two videos come from the fantastic CreativeCOW tutorial series, Premiere Pro Basics (CS6 and Above) which was created by Andrew Devis. These videos were created with an older version of Premiere, but all of the effects and techniques will likely be applicable for many years to come.
Here are two videos from that series, which cover some of the best methods for pulling a fantastic key using only the native Premiere effects. And if learning to pull a key isn't motivation enough, you should at least watch it to see a fluffy blue puppet get shot in the face.
There are a couple of techniques here that can greatly improve the quality of the keys that you pull inside of Premiere (or After Effects for that matter). First is using the Garbage Matte effect (either 4 or 8 point) to mask out the areas of the frame that your subject doesn't cross. Not only can this save you quite a bit of time in the rendering process (depending on your computer), but oftentimes it can help you get rid of parts of the green screen that aren't as evenly lit as they should be, which makes for an easier time once you start keying.
Next up is Adobe's Ultra Key effect. For the actual keying process, the presets are your friend. Once I choose a color to be keyed, I always select the "Aggressive" preset, because it invariably gets me closest to the result that I want. However, it's really important to pull back on a few of the controls in the "Matte Cleanup" section of the effect to make sure that you're not drastically and unnaturally flattening out your image. Also, I recommend building up a collection of keying presets that work best for you. This single step can save you boatloads of time when using the Ultra Key effect in the future.
Last but certainly not least is Devis' use of the Alpha Glow effect. This process was new to me, but having tried it now, it's amazing just how noticeable of a difference it can make in terms of making a subject blend into the environment behind them. However, it's important to be fairly conservative when adding in the Alpha Glow, because the line between glorious blending effect and unnatural glow is an extremely fine one.
Make sure to check out the rest of the videos in the CreativeCOW Premiere Pro Basics (CS6 and Above) series. It's easily one of my favorite Premiere resources on the entirety of the interwebs.
What do you guys think of using this combination of effects in order to pull a key inside of Premiere? What other techniques have you used to pull better keys in your NLE of choice? Let us know down in the comments!
