In high school–as a child of the 80’s, and an adolescent of the 90’s–with a passion for film and photography, and immersed in an excellent high school visual arts program, I remember being captivated by the concept and execution of shooting composite content on blue screen. Even at that time, the concept of blue screen keying and compositing was so pervasive to the public consciousness that I did not hesitate to confidently ask my instructor if I could shoot one of my videos for a class project on the blue screen. Naturally, the school must be equipped with a blue screen studio!
Of course, I was met with a blank stare and more questions than answers. Instead, I ended up editing together an entirely redubbed farcical version of The Godfather, and a series of short comedic vignettes chronicling the exploits of a miniature ‘Animal’ Muppet hand puppet lurking around the school cafeteria terrorizing unwitting diners. I got an A+ that year.
So much has changed since those glorious days of mystical youthful wonder. Most notably, the blues have turned to green. Also, the Muppets aren’t as popular.
Now, as both a fully grown adult man, and fully grown professional video producer, when engaging with clients, the question or request of green screen can be a frequent conversation. While it is certainly a fair item for consideration–the technology now exists for any reasonably experienced producer to shoot something on a simple canvas green screen backdrop and key it out–but, therein lies the universal question: just because you can do it, should you do it?
While green screen can be–at best, a valuable tool within a production, augmenting the overall content and surrounding clips–at worst, or most likely (unless you are contracting a firm that definitively specializes in green screen keying and compositing), it can come off as amateurish and unnecessary to the production.
As a client, your main question needs to be: although I may be interested in the concept of green screen, do I really need green screen? Beyond that, and of equal importance, the question is: does the contractor have the skills to expertly produce and key an impeccable green screen composition?
Personally, I tend to steer clients away from green screen. There is nothing wrong with it, per se, but more often than not, in the typical production, an expertly framed shot with appropriate lenses, in an interesting or related location will resonate with viewers exponentially more than dropping in some anonymous stock footage background just because it is ‘modern’, or ‘industrial’, or ‘cool.’
For videographers and video producers in the freelance, mid-market arena with little experience in green screen, I would take pause to consider what is truly required for effective, key-quality compositing before committing to that production whether it is you or anyone else doing the post-production on that project.
There are plenty of learnings and expertise to develop in the field of green screen and visual effects compositing. You may know plenty of the basics, or none. Either way, do your research and personal field tests if you are unfamiliar with the methods, but keep a few cornerstones in the back of your mind:
More bright is more right! First and foremost, you need to light the green screen adequately, and evenly. Any wrinkles, crinkles, or creases on a dimly lit background are going to standout in post-production and potentially cause problems when you are trying to key it out. Especially if the problem areas occur directly behind your subject.
Once you light your screen correctly, make sure you light your subject properly. That doesn’t mean ‘wash out your subject with even, high key lighting’, it just means light your subject adequate for camera capture, and/or for relevant lighting that might need to match the lighting of the background you plant to key in later. A seasoned, Industrial Light and Magic green screen expert will tell you far more than I can, but I am not talking about shooting sequences for Star Wars, I’m talking about shooting the type of green screen that 99% of filmmakers and mid-market commercial producers might be asked to execute throughout the year.
To make your life easier–especially if you are shooting simple interview sequences with a seated subject for common practice keying–in-camera, shoot at the highest resolution possible, with an at least reasonably sharp iris setting. If your lighting is not adequate on the subject (or background), and you shoot with a very shallow depth of field (f1.8 or 2.4, for example), your focal plane will be extremely detrimental to your ability to successfully isolate your subject from the background. At such shallow depth of field as in the f1-2 range, your subject’s nose and eyes, and cheeks might be in crisp focus, but just inches beyond, their hair outline–the most critical area for separating from the green background key–will be definitively out of focus. When shooting at a low resolution, grainy ISO, with a poorly keyed background, and an out of focus hairline (or glasses, or other details of the figure’s outline), your footage may very well be impossible to key out.
Again, a fair amount of experimentation in both lighting, shooting, and then doing some post-production keying is recommended for anyone who is unfamiliar with the process. Afford yourself at least one good trial run with some of those basics in mind before you commit to a paid green screen project. And, of course, there are a lots of great tutorials online to familiarize yourself with the process, and more in-depth techniques.
Green screen may be a commonly known technique, but it will forever remain best achieved by those with a professional level of execution. That doesn’t mean high-end, or expensive, it just means professional: well prepared, experienced, and well researched. And, again, to reiterate, only done when necessary. A natural, captivating environmental background with a well-lit subject, in my opinion, is always the best choice whenever possible.