Ok so you ordered a chroma key screen off a photography website but you're not entirely sure how to use it, or maybe you went to spotlight and bought some bright green material. Truth is you can get pretty good results with either, if you know what to do with it. Here are our tips for getting the most out of your green screen.
While you probably don't need a 5m x 5m green screen, it is important that the green screen is large enough to frame the actor/item and any action they may produce. For example, if you're wanting a shot of your friend doing jumping jacks, make sure that the green screen is wide enough to to frame their arms when they're at their widest, otherwise their hands could get cut off when you edit the video. The smaller the subject, the easier it can be to get a suitable screen, so you could practise with your pets or some toys to start with.
KEEP IT TIGHT
Make sure the screen doesn't have deep creases or waves in it. Shadow is harder to key and will probably show up in the final video. We use light stands and crocodile clips for the sides of our screen to keep it nice and flat. We also have a hand garment steamer which helps with creasing when we haven't used the screen in a while. We got ours from Kmart for about $16 and it's worked fine for a year and counting.
As well as keeping the screen tight, you need to keep the lighting even. This can be hard depending on how many lights you have. In this picture you can see just how much of a difference you can make with lighting. Ideally you have two lights just for the screen then seperate lights for your subject. You can get a away with natural light if your subject is far enough away from the screen to stop any of their shadows from showing on the screen. This will require a larger screen though, as the screen will be further away.
Think about what kind of look you are trying to achieve. If you have a particular background you are trying to match, lighting can help tremendously. If the background is a dark alley with one street light leaking in from the left, then light your subject with one light coming from the left. The subject lighting can make all the difference when merging the action with the background so take some time and break down what the lighting should be.
FIX IT IN POST
Green screen can be quite forgiving, so you got a few creases in the screen or the actor kind of trips on a bunched up bit on the floor, most of the time you can play with the framing and the keying to make something look passable. We use Premiere Pro's Ultra Key and it does the trick for 90% of what we need. Just use the eye drop tool on the green screen and it's halfway there. We usually boost the pedestal a bit in the settings then we're good to go.
IN THE PALM OF YOUR HAND
There are apps you can download for your phone if you can't get Premiere Pro for whatever reason, and these apps will key green screen in a much simpler way. Green Screen Live Video Record is one to look at but honestly just type green screen app and iTunes or Android and see what will best fit your project.
JUST HAVE SOME FUN
If you're just learning or practising then have some fun with it. Green screen is only really limited to your imagination so play around with some weird stuff to see what's possible. You could try green screening yourself into your favourite movie or TV show or make a fake overseas travel album. It's just a bit of fun and you can learn a lot by playing around with controls and seeing what works best for you and your set up.
So those are our tips, if you have any questions you can leave them in a comment below! We would love to hear from you.
Media Melt is a Video Production Company based in Dunedin, New Zealand. If you have any enquires, feel free to contact us here