A Complete Noob’s Guide to Creative Compositing

When it comes to visual effects, without compositing you don’t have anything than a few disparate bits and bobs floating around in the digital ether. A cloud of smoke here. A beautifully crafted CG spaceship there. A horde of screaming civilians stampeding in front of a green screen. A lovingly crafted plate of a scorched and decimated Trafalgar Square. All floating about, disconnected. You don’t have an ad or TikTok post or feature film. You certainly don’t have a story.

Compositing is the essential and surprisingly subtle craft that brings all elements together. It’s vital to the success of any project that involves VFX - but for non-experts, like marketers and creatives, it can be a mystifying and even intimidating element of the post production. There’s a lot of tricky jargon to navigate, and for the layperson, while you may be able to identify when something doesn’t look quite right, it can be hard to identify or articulate why.

The good news though, is that there’s no shame in not knowing the intricacies of the craft and anything that you’re not sure about. Overwhelmingly, VFX artists and producers are more than happy to clarify uncertainties.

“Don’t be afraid to ask questions,” says Joe Tang, senior Flame artist at Absolute Post in London. “Most compositors, if they have the time, like to talk about what they are doing.”

That’s why we’ve brought together experts from across the VFX world to take readers through the key creative elements of this often poorly understood craft.

First things first, for many the phrase ‘compositing’ itself may feel like a bit of impenetrable jargon. So what is it?

“Compositing is essentially taking all the shot elements, foreground/background plates, any additional set extensions, CG characters and such and making them all fit together to make it look as if it was shot at the same time by the same camera,” explains Becky Clay VFX Supervisor at Untold Studios. “We are pretty much the end of the VFX process and work very closely with lighting, paint and roto artists. Some jobs require a high level of realism like our film and episodic work, and others with the world of motion graphics a bit, and although your shots might be abstract, your job as a compositor is to achieve the overall look the director has in mind, whilst keeping continuity between shots and making visually stunning images.”

Liciani Vargas, is compositing supervisor at Rodeo FX, a VFX house with offices across Canada and in Los Angeles. For her, the key word to bear in mind for compositing is ‘integration’. “Compositing is all about integration, to recreate an image to make it look like that's how it was shot in the first place. So all the elements need to be well balanced in terms of colour, brightness, saturation, in the correct scale and perspective, respecting lenses and camera aspects, matching chromatic aberration, lens flare, distortion, defocus, grain.”

Darren Achim, who is co-head of VFX at Alter Ego, another high end Canadian company, suggests that people who are struggling to get their head around the concept of compositing think about it this way: “I'd say stickers are a good metaphor to explain compositing, a kid has a big page in a sticker book and a host of trees and other objects that they can stick onto the page, if you stick one sticker over another the topmost sticker will cover over some of the previous sticker. If the stickers have transparent parts they will show the sticker below.”

As with many elements of post and VFX there can be lots of confusing lingo to navigate. We’ve picked out a few frequently used terms.

Deep compositing: a more recent technique and technological advancement that allows compositors to use and manipulate depth data 

Flame: a specialist VFX software made by Autodesk

Keying: Chroma keying or green screening, and is a way of combining images using colour channels - keying is the process of removing green backgrounds

Nuke: a specialist VFX software made by The Foundry

Plates: each individual filmed or CG image used by a compositor in an shot is known as a plate

Roto: comes from the animation technique where animators would trace filmed images by hand - in VFX roto is also about manually tracing objects in a shot to separate them and create new images or to cut out unwanted elements

Jessica Bagby at Rodeo explains, “Roto is isolating specific images or elements that were on the plate to play with them so that the final compositing looks like a real image. Sometimes the plate has a green screen, but not always a full green screen, then you need to clean it in order for the composites to be able to key it in one go. 

“On Stranger Things 4 for example, we worked on all the little specs that happen in the Upside Down. When it comes to adding those specs in CG, it's the comp work. But when people are moving in the shot, we need to have the right angle of those floating specs and that's where the roto department comes in. Same with the tentacles interacting with the actors or removing the wires when a character is being pulled around, or even the clothes are being pulled by the wires.”

When working on a project that involves compositing, there are a few things to bear in mind when trying to get what you need (and what you don’t even know you need!) from the compositing team.

The first, is to start speaking to the compositing team early. Though it comes relatively late in the VFX and post production pipeline, compositing shouldn’t be an afterthought as it’s the keystone that holds all other elements together.

Michael Baker, compositing supervisor at Framestore says, “It's always great to get your compositing team into the discussion as early as you can. Compositing is a fast and a  flexible part of the pipeline so knowing what the client/director is looking for can help us suggest some ideas that might save time or just get the most mileage out of the plates or assets.”

A bit of early prep and extra time built in also allows compositors to tackle any unexpected challenges that arise from the shoot itself. David Whitely, another co-founder at Alter Ego says, “Time. It’s all about time. It takes time to really make things look good. As a compositor on commercial jobs we are often required to pull off a hundred tasks on any given job. Shoots don’t always go as planned and the list of things that need to get fixed or completed exponentially grows throughout the process. Most of the time we’re able to facilitate them but just given that extra bit of time to pre plan before the shoot or just a bit more time in post then the final result will inevitably look better. Sometimes it feels like we are just trying to get through the sheer amount of volume and I don’t want the quality to suffer because of that.”  

Jim Allen is creative director, VFX at No.8. He points out that these early conversations can not only help sense check budget and ambitions, but also shed light on new, better options fuelled by new tech before the shoot starts.

“Speak to your VFX partner early in the process, at script stage preferably. The earlier the VFX team is involved the better the final film and the journey getting there will be,” says Jim. “We can help sense check creative ideas and suggest new ideas if the budget won’t stretch to, let’s say, that location shoot on Mars the creative team have their hearts set on.  New technologies and techniques are emerging all the time that directors and creative teams may not be aware of so it definitely pays to give us a call.”

Federico Quiros, at Argentinian VFX shop La Posta, advises that good VFX supervisor can ensure that the filmed elements are usable. “Involve a supervisor from the start, explain what you need and listen to what elements would be needed to capture on set. It may be extra plates, light probes, measurements, scans, etc.,” he says. “If you are going to shoot greenscreen elements, matching the light to the background plates is imperative above all else.”

In fact, communication shouldn’t just happen at the start of a project, but throughout. This is particularly important when stakeholders and makers are spread across the globe, says Hannah Wilk, a flame artist at Blacksmith. “Communication is more important now than ever. Nuance is lost when you’re reading someone else’s words in your own voice. Working on a project now, your artists, and your servers may be in different locations. As jobs become more global, data management becomes a necessity. If servers are in NYC but artists need data synced to LA, this adds time and is another factor that needs to be taken into account, for the project’s schedule. Compositors need media to composite, and they need to have access to it, no matter where they are.”

It’s also important to understand that compositing is an iterative process, Darren Achim points out. The first pass might freak you out but remember it’s a case of multiple passes and refinements. “The other concept to keep in mind in VFX is iterations. An approved shot is usually never version one, so producers and clients should build an understanding that time equals iterations and generally speaking more iterations usually equals a superior product.”

It’s important to understand what kind of story you’re telling and what sort of overall aesthetic you’re aiming to achieve, as that will then dictate how the team approaches the job. Compositing isn’t a one-size-fits-all affair, it’s an art and craft that carries thousands of possibilities. Some jobs will demand that the compositing is nigh on invisible, aiming to mirror reality as closely as possible - but other projects might demand a grungy, grimy, hyper-textured feel, and others yet might benefit from a whimsical, surreal appearance. 

Hannah Wilk at Blacksmith likens compositing to a language, with its own syntax and grammar, which can be recombined to express a range of different feelings or visual aesthetics.

“If you are looking for invisible compositing, it should be just that - invisible. It should be as if it hasn’t been composited at all. Clean up done without calling attention to itself. If you are going for the more upfront form of compositing, the creative work is much more in your face. Any creative language defined in the spot is executed upon in an attempt to sell through the gravitas of a moment. The shot should build on the spot’s rules and creative language - this doesn’t need to be solely based on reality. The rules of physics can be broken in order to add artistic pull to the shot,” she says. “The language of compositing is just that, a language. It helps if the artist knows proper syntax and grammar.”

If you can understand what it is that your compositing team is trying to achieve as a feat of cinematic storytelling rather than as a flawless mirror of reality, it can help to make sure that you and they are pulling in the right direction.

“It all depends on what you’re trying to achieve creatively: is it meant to look photoreal, or be something more stylised?” says Joe Tang at Absolute Post. “Generally, I would look at a few major things before getting into finer details. Is the lighting correct? Does it match the scene and are the levels right? Is the perspective and size of composited objects correct, and if the camera moves, does everything track and maintain the right parallax? Finally is the focus and depth of field correct?”

According to Elad Offer, ECD and VFX supervisor at The-Artery, the key is to think ‘story first’. All decisions should be in service of the story rather than being driven by trends or what new tech people want to play with.

“At The-Artery the approach is simple: the story is always the top priority,” he says. “Regardless of the tools or capabilities available, the goal is to bring the director or agency's creative vision to life and make sure the final composite tells the right story. This involves directing the viewer's attention to the right spots, creating the right mood and atmosphere, and highlighting key elements of the narrative.”

Elad dives deeper, explaining how this works in practice. “Sometimes this means making an invisible composite, where nothing stands out as being added or removed from the scene. Other times, it involves crafting the image in a more deliberate way, removing distracting elements, darkening areas that draw attention away from the main story point, and highlighting the elements that should take centre stage,” he says. “In fact, there are times when a compositor must even deviate from what is technically correct in order to better serve the story, cheating depth of field or manipulating light to focus on an object that might not naturally draw the eye.”

So, you’ve been pulled in to check out the VFX shots and your ECD has asked you to give them a once over. What should you be looking for or checking out?

Nick Whiteley is VFX & Compositing Supervisor at The Embassy and he says that while people might be able to feel if an image looks off, in order to articulate why, they need to think about three elements in particular. “Our brains are already pretty adept at detecting whether something is real or not and whether something belongs in an image - we have an innate ability to detect things that are out-of-place,” he says. “The closer we can get to fooling our eyes, the better the final comp will be. If I was to break this down, I think you could distil this into three main points. Lighting, colour and edges.”

A big part of what makes objects or elements seem detached from the scene is lighting mismatch - especially lighting direction. This also contributes to where shadows would fall and how objects are positioned in space. Less so for flat lighting conditions - although this poses other challenges. Colour is a large topic, but very broadly speaking, whatever is being composited into the shot, must have the same tones as the plate. Matching black levels, white balance, brightness. Perhaps there is an overall lift in the plate or it is an atmospheric, hazy environment. Last but not least, If we’re talking about elements shot on green, then a lot of work has to be done on edges. Not only the fine detail and the inevitable dark edges, but edge scattering, despilled edges and edge blending. 

Genevieve Camilleri, VFX supervisor with Alt VFX in Australia agrees that lighting and colour are key elements when assessing a composite. She also suggests looking at the level of detail between different elements in a scene - do a hazy, grainy filmed element, a chunky entirely smooth polygon and a highly intricate 4k piece of CG look believable together?

“When you look at a shot for the very first time and you can not actually tell what is and is not real then you know the shot has been composited well,” she says “In general what to look out for is how well does the lighting, colour temperature and level of detail of the element you are composting match the original plate it is being incorporated into.”

It all boils down to one word for David Whiteson at Alter Ego. “Integration is always key. Whether it’s a simple green screen composite over a background or combining CGI with practically shot plates you always want it to feel integrated. The more real world cues that help the viewer not question the composite, the better. Atmosphere, lighting or  imperfections all help with integration and realism. Keying hair is a perfect example. Maintaining  all those subtle wispy “fly away” hairs really makes it feel not keyed and real.”

Duncan Malcolm, is head of 2D and Creative Director, at Glassworks London and he says that, while there are all manner of technicalities that a pro would look at, overall it’s about how the shot hangs together and whether it matches the vision laid out by the director.

“There are many technical aspects that get checked by a compositor, such as matte edges, tracking, grain-matching, depth of field and lens effects like chromatic aberration. However, the core skills of a good compositor are more about how to deal with the shot as a whole and how the elements balance together,” he says. “It is important to check if the shot works as you imagine it was intended to by the director - what tricks have they used to make the shot work, either to sit everything together seamlessly or to draw attention to one part or the other? A great compositor will use numerous tricks with subtlety and wisdom such that they become invisible in their own right! Ironically, it’s often easier to see good compositing skills on shots where the elements supplied from the shoot or by CG dept aren't as well thought out as they might be! Then, when the end result works as a cohesive shot, the hard work in comp is much more apparent.”

As with any visual artform or craft, the foundation for a true appreciation of compositing lies in our ability to observe the real world and spot the details that others might overlook. The interactions between objects, the effects of natural conditions, the role and changeability of light. 

“When you are out and going about your everyday life, start to take a look around at the finer detail of objects and environments that surround you,” says Genevieve Camilleri. “Assess how things react to light and interact with each other. Through this you will begin to train your eye to take note of all the small details needed to successfully composite a VFX shot.”

“I’d advise people to think about the real world, look at how it works, why glass looks like it does, how lights work,” says Duncan. “Study photographs and look up when you’re walking down the street. Watch how the light glints off the windows and how the shadows work. If you want to start to work in compositing, then the best advice is to start simply and learn ‘why’ alongside ‘how’. Take photos, paint pictures, use Photoshop... The ability to use compositing software is obviously important, but a real understanding of images, of real things, is the most important thing to understand.”

It won’t happen overnight, but it’s a muscle that, when developed, won’t just help you when assessing compositing, but all sorts of aspects of craft and design.

Compositing is still a highly technical skill - and we’ll be delving into some specific challenges and technological developments in future articles - but perhaps the most important thing for non-specialists to do when navigating a project that requires heavy compositing for the first time is to understand how creative compositors can help them achieve the best, and to allow them the time to do it.

Elad at The-Artery sums it up beautifully. “Many years ago a mentor taught me that we are making movie magic: we create movie magic, not necessarily recreating reality. Compositors have the ability to shape light, narrative, and composition to tell the story in the most impactful way possible. This approach has become the true north for the team at The-Artery and has helped us stand out as one of the most creative and innovative visual effects studios in the industry.

“In the end, it's the combination of technical expertise, artistic vision, and a deep understanding of storytelling that makes a compositor truly exceptional. With the right balance of these elements, compositors have the power to create images that are both technically stunning and emotionally resonant, bringing the audience into the world of the story and immersing them in a truly unforgettable experience.”