VFX vs CGI: Key Differences Every Filmmaker Must Know
VFX (Visual Effects) is any imagery created, altered, or enhanced for a film that wasn’t captured in-camera. CGI (Computer-Generated Imagery) is a subset of VFX—purely digital 3-D or 2-D elements built inside a computer. All CGI is VFX, but practical explosions, matte paintings, and wire removal are VFX without being CGI.
People hear “CGI explosion” in behind-the-scenes clips and assume every green-screen shot is CGI, forgetting that stunt doubles, miniatures, and even makeup prosthetics count as VFX too. The confusion grows when marketing blurbs swap the terms to sound tech-savvy, leaving filmmakers unsure which pipeline to budget for.
Key Differences
VFX is the umbrella craft; CGI is the digital paint. VFX teams composite practical plates, while CGI artists model, texture, and light pixels. Budgets differ: a practical car flip (VFX) may cost less than a full CGI city collapse. Schedules vary—CGI renders overnight, practical VFX waits for golden hour.
Which One Should You Choose?
Need photoreal crowds on a rooftop? Go CGI. Need subtle blood removal or sky replacement? Lean on VFX compositing. Indie filmmakers often blend both: shoot a real alley, then drop a CGI dragon in post. Match your script’s scope, timeline, and hardware before choosing.
Examples and Daily Life
In Stranger Things, the Upside Down vines are CGI, but the flickering practical lights on set are VFX augmentation. Your iPhone portrait mode blur is real-time VFX; the dancing hotdog filter is CGI. Even weather apps use both: satellite footage (VFX) plus animated raindrops (CGI).
Can CGI ever look fully real?
Yes—when lighting, physics, and compositing mimic reality. The T-Rex in Jurassic Park still fools eyes because practical references guided the CGI.
Do indie films always need CGI?
No. Clever VFX like forced perspective, miniatures, or stock elements can sell scale without expensive render farms.
Is motion capture VFX or CGI?
Both. Actors’ performances (VFX) are captured; digital doubles (CGI) are created from that data.