Earlier this month, both our full-time and part-time Compositing course students were offered the opportunity to film their own green screen chromakey shots that would help to enhance their showreels, with unique cinematic values. The shooting, which took place over 2 days at Escape Studios, saw the acquisition of 16 different shots and set-ups, through more than 80 takes.
But here is the real story behind this tale - an unexpected romance between Cinematography and Visual Effects…
Chromakey is the code name for these green or blue backgrounds commonly seen on film sets whenever visual effects are involved. Usually associated with computers and digital images these chromakeys actually made their first appearance as early as the 1930’s to create what was then known as ‘travelling mattes’.
In the fairly short history of filmmaking, cinematography arguably came first and suddenly saw its own premises being invaded by a bunch of rather unwelcome newcomers, the ‘Visual Effects’. In other words, VFX and Cinematography is an arranged marriage. They’ve been set up. Production necessities, as well as the unescapable development of technology, have pushed VFX and Cinematography into each other’s arms. But it was not exactly love at first sight.
My own professional journey in the film industry, from camera operator to VFX artist and from Harry Potter to Ex Machina, lead me to experience and realise how crucial this relationship has now become for modern filmmaking. And the more you understand it, the better you get at the game.
Among the tumultuous but no less fruitful encounters between cinematography and visual effects, Chromakey is actually one of the most interesting and spectacular points of convergence.
These green screens are like our digital gardens where we grow visual flowers for the delight of the audience.
When it comes to chromakey light is often a contentious topic. Put very simply, the light required forchromakeys, has hardly anything to do with the light demanded by the story. Cinematographers or d.o.p.(directors of photography) face the daunting challenge to try and reconcile a technical light, necessary for the VFX, and an artistic light, devised to serve the narrative.
These two types of light usually contradict each other because their respective intentions and purposeare fundamentally antagonistic. The light needed for the chromakey screens must be even, soft, and itsintensity must be such that the value of exposure for the screen colour (blue or green) ideally standsabove the remaining two of the 3 colours (RGB) which form the final recorded image.
On the other hand the light designed for the story and the protagonists can virtually embrace any colour,quality and intensity there is in the vast spectrum of human emotions and situations. So clearly the ‘VFX’ light of the screen and the dramatic light of the story don’t agree.
To solve these contradictory lighting requirements the advise frequently heard around is to position the chromakey screen as far away as possible from the foreground, therefore preventing each type of light, artistic and technical, to compromise to much for the one another. But this is not always possible or effective.
First, the further the distance between the foreground and the background, the bigger the screen required. Then, if the director demands a ‘long shot’ or ‘establishing shot’ where characters are seen head to toe in the environment, the feet of the actors must be in contact with the chromakey. And that precise area, where foreground and background connect, is where technical and artistic lights clash head-on. From a lighting point of view, it’s an absolute contradiction.
A common misconception is that VFX shots and the lighting especially should be as neutral as possible with the least amount of intentions factored into it. If neutrality is relevant in terms of exposure and chromakey it certainly is a mistake in terms of light direction and narrative.
In fact, the only true practical solution is to compromise. But compromising doesn’t mean giving up. It’s on the contrary a very demanding task which requires sharp skills. It’s all about trying to bring thetechnical and narrative lights to coexist, to accommodate each other without suffering too much from one another.
In few words the terms of such a delicate negotiations should ideally go as follows:
The light built for the action should have priority in term of direction and quality because theseparameters are particularly difficult to rebuilt in post-production. This will therefore impact the consistency of the chromakey which may be affected by some shadows and variation of light. On the other hand, the exposure, traditional remit of the cinematographer, should be set for the chromakey and the intensity of the narrative lights would then be determined accordingly.
With a little bit of good will from each party the combined effort will ultimately benefit the film.
VFX = Reversed Cinematography
You don’t have to be a mechanic to drive a car but the fact is that Formula 1 drivers always have the most intimate and perfect knowledge of the car they drive. Same for VFX. You need to know the DNA ofimages to be able to create them digitally. And that’s what Cinematography provides to VFX artists.
Learning VFX is not just about learning a software. Knowing the tool is only the bare minimum expected from a VFX artist. In fact the best possible VFX tool is not the software but the human input, the vision of the Artist.
Therefore to become a top VFX Artist, it’s essential to understand what an image is made of, to connect the dots between the different components and stages of image making, in other word: to look beyond the computer screen, to get the big picture.
Whether we are cinematographers or VFX artists we are making the same image, we are dealing with the same parameters at two ends of the same spectrum. Cinematographers and VFX artists may use very different tools but they share the same medium. In that respect the practice of Visual Effects is actually ‘Reversed Cinematography’. And contrary to the tools - cameras or software - the different attributes of an image remain universal, timeless and a highly transferable knowledge.
That’s the very reason why it is so necessary for VFX artists to learn cinematography and get to know what an image is made of.
If this was not enough to make the case for VFX Cinematography it only takes to look around and see how much new media of all kind directly draw inspiration from Cinematographic images. Even animation and games, so eager to replicate the world in the most photo-realistic way, borrow the codes, therepresentation, the visual signatures and optical artefacts of a camera.
So there is indeed a lot to benefit from a little bit of cinematography in our digital lives.
Escape Studios has established its reputation with a unique industry focused education. And these cinematography workshops contribute directly to the making of ‘production ready’ artists, of people able to deliver the Hollywood standard from day one.
The benefit of these sessions for our students is immediate. At a practical level, everyone get the chanceto devise and shoot an original footage which will then receive various visual effects treatments. Doing so, our student’s showreel are not only unique but get a significant boost in term of quality, not to mention the fantastic round trip through image making provided by the experience. From a longer term perspective, cinematography helps future VFX artists to nurture that critical eye so essential when working in the industry.
In short, if you want to become a top VFX artist you need to know how to create an image and understand what an image is made of. As simple as that. Providing camera workshop and cinematography courses to our VFX students addresses that exact point.
The different assets created during the film workshop will be integrated through compositing in order toform a complete cinematic shot. The main VFX technique associated to this particular green screen setup is Keying or the art of extracting of foreground from a background. The purpose is to enable the photorealistic combination of a variety of elements which don’t originally belong to the same time space. These chromakey plates filmed by our VFX students actually make use of the entire spectrum of skills and typical tasks involved in compositing (Set extension, Camera tracking. CG integration, Grading, etc...)
Originally developed as a stand alone short course, these Cinematography workshops for VFX artists enjoy growing interest and relentless demands from students to be routinely incorporated in the current Compositing curriculum. We also have increasing enquiries from 3D and Games students, eager to create photo realistic productions and therefore desperately in need of solid foundations in cinematography. So hopefully more and more exciting filming to come in our digital garden.
Written By Clement Gharini, Cinematography Tutor