What it does
The look of an old tube monitor: glowing phosphor stripes, slight color fringing, and a darkened vignette.
A CRT builds its picture with electron beams sweeping across a glass face coated in phosphor, and everything we recognize as "the CRT look" is that construction showing through. The picture is not made of square pixels; it is made of glowing red, green, and blue elements arranged by a mask, and the geometry of that mask is the texture of the screen.
There were two great mask designs, and they look different. Shadow-mask tubes arrange the phosphors in triads of round dots, the texture of most consumer TVs. Aperture-grille tubes, Sony’s Trinitron most famously, use unbroken vertical stripes, which read as fine vertical lines and made those monitors look sharper and brighter. A convincing CRT effect lets you pick the mask, because the mask is the era: dot triads say 1970s living room, stripes say 1990s graphics workstation.
On top of the mask sit the tube’s optical flaws: the three beams never converge perfectly, so edges fringe into red and blue; the glass face falls off toward the corners into a vignette. Because the phosphor pattern is generated per frame at whatever scale you choose, it stays crisp on video and can be pushed from a subtle screen texture to a full wall-of-pixels signboard look.
Signature looks
Trinitron desktop
Fine aperture-grille stripes, gentle fringing, a light vignette. The crisp glow of a 1990s graphics monitor.
Living-room triads
Coarse shadow-mask dots with soft phosphor bloom. Sit too close to the family TV and this is what you saw.
Signboard
The mask scaled up until each phosphor is a visible lamp, turning any footage into a giant public display.
Try it on your own footage
This effect runs live in the Modulate editor, free with no signup — or start from the free tool page for a guided setup.
Common questions
What is a CRT effect?
A CRT effect simulates the appearance of a cathode-ray-tube screen: the phosphor stripe or dot-triad pattern of the mask, color fringing from beam misconvergence, and the vignetted falloff of the glass face. Applied to modern footage, it reads as retro display hardware rather than retro film.
What is the difference between a shadow mask and an aperture grille?
Both control which phosphor each electron beam can hit. A shadow mask is a plate of holes producing triads of round dots, the standard for consumer TVs. An aperture grille is a set of taut vertical wires producing unbroken stripes, used by Sony Trinitron tubes, and it passed more light so those screens looked brighter and sharper.
Is a CRT effect the same as a VHS effect?
No, they simulate different machines. CRT artifacts come from the display: phosphor patterns, fringing, vignette. VHS artifacts come from the tape and player: wobble, tracking errors, chroma bleed, dropouts. Footage from the era was usually both at once, which is why the two effects stack so well.
Why do CRT screens look striped in photos and films?
The stripes are the mask itself resolving. A camera close to a CRT resolves the individual phosphor stripes or triads that the eye blends at normal distance, and film scenes set on old monitors lean on that texture to say "screen". The effect reproduces exactly that pattern.
How do I get the CRT look on my own footage?
Apply a CRT effect that generates the phosphor pattern rather than overlaying a static texture, so the mask stays crisp at any resolution. In Modulate the CRT Monitor effect runs live on images and video in the editor, and it stacks with VHS and NTSC effects for a complete period setup.
Related effects
VHS effect
The full worn videotape package: color bleed, static, dropouts, wobble, and tracking errors.
NTSC effect
The look of an analog TV broadcast: soft edges, color bleed, scanlines, and signal noise.
Dither effect
Early computer graphics look: the image is rebuilt from tiny dot patterns and a limited color palette.