When you hear “CGI” or “VFX,” you might picture blockbuster-style explosions, flying dragons, or futuristic cityscapes. But in the world of television production, visual effects (VFX) aren’t always about spectacle. In fact, some of the most impressive work is completely invisible.

Here’s your guide to the behind-the-scenes lingo of this digital magic.

VFX (Visual Effects)

This is the umbrella term for any image manipulation done in post-production that wasn’t captured on camera. 

If it’s added or altered after the footage is shot- think digital environments, crowd duplication, or weather effects- it’s VFX. Production companies can use VFX to save costs, enhance realism, or fix mistakes without need for an expensive reshoot.

CGI (Computer-Generated Imagery)

CGI is a type of VFX. It refers specifically to images or elements created entirely using computer software. 

These could be detailed 3D models (like a spaceship), or more realistic enhancements (like a digitally generated building extension or crowd). 

CGI blends seamlessly into live-action footage to make the unreal feel completely real. If you’ve ever watched a scene and not realised part of it was fake, that’s some good CGI.

SFX (Special Effects)

SFX is where things get practical. Unlike VFX and CGI, SFX happens on set during filming. 

This includes physical effects like smoke, rain machines, fake blood, pyrotechnics, or breakaway props. Think of it as the tangible side of TV illusions. SFX artists create the illusions that are captured with a camera rather than added in post.

Clean-up Work

On TV, a lot of, in fact maybe even most of  the work is “clean-up”. Digitally erasing stray hairs, removing unwanted signs or logos, or fixing continuity errors (like a coffee cup left in the shot- yes, that one). 

Often preceded on set by a much dreaded: ‘we’ll have to fix that in post’. It’s the unsung hero of the production process.

Compositing

This is the process of combining multiple visual elements into a single image. 

A scene might be filmed on green screen, then layered with a CGI background, practical SFX smoke, and colour correction; the compositor’s job is to ensure it all looks like one seamless scene.

Plate Shot

A “plate” is a clean shot- usually of a background- with no actors or movement. 

It’s used as a base layer for adding effects later, like duplicating actors, placing CGI elements, or fixing errors. If the director knows something will be added in post, a plate shot is often recorded just in case.

The Bottom Line?

Not all digital magic is loud or flashy, in fact, most of what we see isn’t.

On a single episode of a VFX-heavy show (think The Witcher, Stranger Things, or Doctor Who) there could be 20 to 200 VFX artists involved– including modellers, compositors, texture artists, rotoscope teams, and more. 

Their work keeps the magic alive- and you might never even notice it was there.