A black number on a grey board going down every second, often when a full circle happens, and usually won't actually reach the end. When it appears, chances are it's a reference to old cinematic projections and is meant to make an intro or something else more classic.
The technical term for this is a universal film leader, a length of film attached to the beginning of a reel. The countdown assists the projectionist in setting the reel to the start of the program before turning on the projector. It is also meant to help synch the video with the audio since they used to come on two different reels, with a beep meant for every time the number is subtracted.
Compare Melting-Film Effect.
- An old Disney Channel bumper starts off like a normal "clock" countdown, but Mickey Mouse pauses it, removes the circle, and replaces it with three circles that form the part of the DC logo shaped like his head.
- IMAX theaters play such a countdown before movies. Words are shown as if a projector is powered on before switching to proper quality at the number 8.
- Madballs: Gross Jokes starts off with one, with an audience in the background of children shouting "Five! Four! Three! Two! One... Yay!"
- Rock and Rule: While Mok is seducing Angel privately, Omar and Stretch are being sedated by Edison Balls, which reduces them to a catatonic state. Later, the Schlepper brothers find Omar and Stretch still in the reception room, watching an old hologram of Mok's song "Triumph." The hologram ends with a cinematic counting up to six before ending completely.
- The Adventures of Elmo in Grouchland begins with an old film reel. Seeing as the film was based on an Edutainment Show, Ernie has the audience count down along with the numbers.
- Looney Tunes: Back in Action has "Mother" produce a VHS tape that explains the significance of the Blue Monkey Diamond. The tape begins with the cinematic countdown before actor Peter Graves, in an Affectionate Parody of his Jim Phelps role, narrates the mystic power of the Blue Monkey: it has the power to transmute people into monkeys, and vice versa. The comic subtext is that the US government can house an Elaborate Underground Base (Area 52) that still uses antiquated methods of counter-intelligence.
- Report is an impressionistic short film that is a Stock Footage montage of clips of assassination of John F. Kennedy. At the halfway point there is a clip of alternating black and white film leader counting down. The flickering film leader suggests the fading consciousness of a dying man.
- Space Jam: Since the Nerdlucks have no idea what basketball is, the Looney Tunes show them a newsreel from The '40s that shows how the game is played (badly) in a public gymnasium. This newsreel begins with the cinematic countdown (3, 2, blank), during which Barnyard Dog throws his box of popcorn at a standing Foghorn Leghorn. Dog grouses, "Down in front!" as the popcorn somehow levels the rooster on impact.
- Amazon: Guardians of Eden: To help replicate the feel of a 1950s serial, the game begins with "PICTURE START" and goes from 5 to 3.
- Garfield: Caught in the Act: Each level starts with one of these countdowns going from 3 to 1 against a background of static.
- Oscar starts its levels with a white-on-black countdown. Downplayed as it looks slightly more modern than the usual examples and goes from 5 to 1, but it still fits the levels being in a cinema.
- Pokémon Black 2 and White 2: The films from Pokestar Studios all have the countdown circle before playing. All of the films are homages of different genres, so the circle fits the aesthetic while still being recognizable as a cinema thing.
- Police Quest IV: Open Season: When Carey is offered to watch a movie in the Third Eye Theater, the film screen shows 5 and 4 (and potentially even a 3, depending on game speed) before the screen goes black and it starts.
- Populous II: Trials of the Olympian Gods shows the opening cinematic in an ancient movie theater of sorts. Fittingly, there's a monochrome counntdown from 5 to 2.
- Power Stone: The first game features this countdown at the very beginning of the intro.
- Sunday Night Suicide: The opening cutscene starts with a Retraux countdown to 2, complete with old-timey film tape artifacts, to resemble a vintage Mickey Mouse cartoon.
- The Three Stooges: After the Stooges see they're in a Ghostbusters II game, the screen cuts to a circle with a number that goes from 5 to 3 and a moving line. It's simplistic due to the NES's limitations.
- Homestar Runner: When you select one of the reels in the Old-Timey toon "Kick the Can", after it finishes loading, the projector shows a circle and a number that goes from 5 to 2 before the short starts.
- Minilife TV: In "Prank Week!", the highlight reel of the pranks pulled during Prank Week begins with a circled countdown, only it's in color and the beeps are replaced with someone saying "Beep sound, beep sound, beep sound, final beep".
- Epic Rap Battles of History: Steven Spielberg's pre-battle intro has one of these in the background.
- As a reference to Chaplin's films coming from old film era, Freshy Kanal's "Mr. Bean vs. Charlie Chaplin" starts with projector and countdown beep sounds before revealing theatre seats and a projection screen where the countdown is happening.
- All Grown Up!'s intro has a classic countdown from 4 to 2 interspersed with footage from the show and colored flashes.
- Being Ian: The intro starts with a countdown from 4 to 1. After that, Ian crashes through the screen in an airplane and the rest of the intro plays out.
- The Fairly OddParents: In Abra-Catastrophe!, Barry Cowlick Jr. puts Timmy in a cinema chair and turns on a projector to show what people wish for during his musical number. Before the projection starts, there is a black-and-white countdown from 3 to 1.
- The pilot of Gravity Falls opens with "HEAD", "SOUND START", "PICTURE START", and a monochrome countdown from 8 to 3 (and 2 very shortly) before the show actually starts.
- Kick Me: This cartoon is a Deranged Animation abstract short about a pair of disembodied legs running around an abstract landscape. In one scene the legs run right into some old-timey film leader that is counting down. The legs keep getting knocked around by the hand of the film leader clock as it sweeps around in a circle.
- In the The Loud House episode "One Flu Over the Loud House", the flashback that explains how Lynn and the twins got the flu is preceded by an old film reel countdown.
- The Patrick Star Show: In "The Yard Sale", when Patrick's grandfather projects a vision of his flashback, it starts with an old-timey grayscale countdown.
- Quack Pack's intro has such a countdown show up on Donald Duck's projector before he's interrupted by his nephews.
- Rejected has one appear before every segment, but only the 3 appears and it flashes away as soon as it ticks down to 2.
- The Simpsons:
- In "Beyond Blunderdome" as the Simpson family about to watch the new improved version of Mel Gibson's remake of Mr. Smith Goes to Washington Homer announces "here comes two!" as the 2 is about to show up.
- In "Natural Born Kissers" when watching an alternate version of Casablanca at the old folks' home, Grandpa announces "Here comes two!" as the 2 is about to show up.