Summary: Flicker caused by the mismatch between the framerate the video being recorded is at and the framerate of a TV set or other video onscreen.
In the age of analog television, TV pictures were transmitted as a series of lines that were drawn on the screen extremely fast. The term for this type of image is "raster," from the Latin "rastrum," meaning "rake." Flatscreens don't do this, and instead produce a moving picture as a series of quick stills, as film does.
During the era in which Raster Vision was a genuine phenomenon, movies that showed television tended to aim for Crystal Clear Picture, either using a picture drop-in or a special TV set with the same refresh rate as a film camera (24 frames per second). Actual TV sets (in North America, at least) refreshed at 59.94 fpsnote , and this speed mismatch produced a strong, unpleasant flicker in the filmed image.
Although precursor examples (such as the holograms in Star Wars) existed, Raster Vision became common when film and television production fully entered the digital age. As with Lens Flare before it, Raster Vision - once an unsightly product of technical limitations - became an aesthetic unto itself. Examples in media are one of two types:
Genuine: A filmed TV set, with flicker and scan lines. Prior to the advent of videotapenote , TV shows (except for Soap Operas) were generally filmed, rather than taped, and will show flickernote . (Recording a TV set with a camera with the same refresh rate and the correct shutter speed doesn't produce flicker). Scan lines are most noticeable on black and white sets, which have a single, uniform layer of greenish-white zinc sulfide on the inside of the picture tube. The different systems for reproducing color have overlaying patterns (known as the Dot Pitch, more info on the other wiki) that obscure the raster effect to a degree.
Simulated: Much more common in 21st century media. Scan lines are often much thicker than they were on CRT televisions - a visibly thick line is impractical for picture reproduction - and appear on flat screens and holograms, neither of which reproduce pictures as raster images. The image may also have more detail than the scan lines should be able to provide.
Raster Vision examples:
- Perhaps the earliest example comes from "Captain TVideo," a spoof on Captain Video that appeared in a 1954 issue of MAD magazine (still a comic book at the time). Every single panel is covered with hand-drawn horizontal lines, which add to the spoof's running joke that the production values of Captain Video were terrible (which, by all accounts, they were).
- Common in the films of the Marvel Cinematic Universe.
- Videodrome: While the film averted the trope by being the first to feature low-flicker television, the trope is used in stylized form on the poster's logo, however.
- Used for a Video Phone showing only the back of the President's head in The Crazies (1973). Had the president turned around, the viewers would have seen it was director George Romero.
- Used in Star Wars Episode IV: A New Hope for the holograms. This is an early use of Raster Vision as an aesthetic - the crummy holograms fit in with the worn-out nature of the tech shown in the movies.
- Seen on the Nostromo's various computer monitors in Alien (but see Alien: Isolation under video games, below).
- Vertical raster bars appear on the TV set inside the Construct in The Matrix.
- Once La Résistance has unlocked the data from the mind of Johnny Mnemonic, J-Bone hijacks the airwaves to wide-band (broadcast) the cure for Neural Attenuation Syndrome to the masses. His broadcast is twitchy and low-resolution, but still coherent. This undermines the Evil Plan of Pharmakom and the Yakuza to keep much of humanity tethered to a cure to the disorder they created.
- In the original RoboCop (1987), the title character sees in raster lines after becoming a cyborg. The same applied to the TV series adaptation.
- On the close-up shots of televisions in Lethal Weapon.
- In the holographic interface in Paycheck.
- Used for some (but not all) video screens in Interstellar.
- Appears on the final TV screen shown in Don't Breathe.
- Used not only for video footage but for the poster of Europa Report.
- Contact features a lot of this, with a whole scene dedicated to showing a science team trying to make sense of a TV signal from deep space.
- Appears on the spaceship's black and white monitors screen in Ascension.
- In the video for "Ghost", part of the Mystery Skulls Animated series, this effect is used for a flashback... as shown in a picture frame...
- The video for "Weird Al" Yankovic's "Word Crimes" includes a snippet recreating the Windows 95 desktop as seen on a CRT monitor.
- Used for the opening seconds of Meghan Trainor's "NO" video.
- Used in the video for "Crack" by The Left Rights (the part that recreates Super Mario Bros.)
- Occurs naturally on the CRT Video Phone screens in Babylon 5.
- Appears in the period-correct screens on Stranger Things.
- Appears on the TV screens in The Man in the High Castle (which, somewhat oddly, are 16:9 CRTs - in the 1960s.)
- Used in the archival footage in the Netflix documentary series Wild Wild Country.
- In order to recreate the feel of the Nostromo from Alien in Alien: Isolation, CRT screens were videotaped, with that footage then dropped into the game and displayed on in-game screens for the proper analog feel.
- Five Nights at Freddy's: Most of the secret minigames that appear since the second installment are made to resemble a typical Atari game, complete with raster vision.
- Used for the dispenser screens in Team Fortress 2.
- Used on the futuristic computer screens of the Combine in Half-Life 2
- Shown in SOMA. Especially odd for the setting, being in the year 2104 using flat-screen monitors.
- Raster lines appear as an overlay on kill screen playbacks in Overwatch.
- This actually has been promoted to a full-on feature on some emulators and retro game compilations, to emulate the look of playing the game on a CRT TV. The reason being is that old game consoles actually did have more pronounced black lines compared to watching TV normally — they displayed in a non-interlaced format where only one of the video fields would get used, and at double the rate it normally would be. With the other field going completely ignored, this gave the image a scan line look and to some degree helped mask the lower resolution of early game consoles. Since some people prefer it to look that way as opposed to ultra-sharp and blocky pixels, this option has become a bit commonplace. Just to name one example, the Stella Atari 2600 emulator includes this option.
- The outro for Game Grumps takes the form of a CRT screen (with the show's logo burned into it).