This is when the screen's Aspect Ratio changes to indicate a shift between eras, to provide an artistic feel to the story or emphasize the intensity of the situation. The switch can be done either by the frame dynamically moving to fill the screen, or by a quick cut to another aspect ratio.
Transitions that happen between installments can signal that a work that started in television's 4:3 ratio has been adapted to the cineplex's 16:9 ratio.
- This PlayStation ad shows the life of a PlayStation fan. It starts off in the PS1 era in 4:3, and when it moves on to the PS2 era, the aspect ratio shifts to 16:9. This reflects the display modes predominantly used by the consoles — most PS1 titles are presented in 4:3 (although a handful do offer 16:9 support), but the PS2 had more games that support widescreen mode though 4:3 is still commonly used at the time. It wasn't until the PS3 onward that widescreen display modes would become the norm.
- DARLING in the FRANXX, uses letterboxing Once per Episode to emphasize particularly important or poignant moments.
Film — Animated
- The Incredibles: The superhero interviews in the beginning are in 4:3 to show that they're in the past. The rest of the film is in 2.39:1.
- Brother Bear switches to Scope after Kenai turns into a bear.
- Done at the beginning of The Triplets of Belleville.
- The Simpsons Movie begins in 1.85:1. When the movie title appears, Professor Frink pushes the frame aside, converting the rest of the movie to 2.39:1.
- The 2013 Mickey Mouse short Get a Horse! starts out on a small screen on black. When Mickey breaks through the screen, the rest of the wide area lights up to reveal the theater the cartoon is playing in. Afterwards, Mickey pulls back the curtains on the theater stage to reveal a wider animated screen underneath.
Film — Live-Action
- The film Popeye starts out with a small screen showing a black-and-white Popeye cartoon. When an animated Popeye notes that he's in the wrong movie, the film switches to widescreen to start the actual movie.
- The IMAX 3D versions of Transformers: Age of Extinction and Transformers: The Last Knight are notorious for doing this to the point where the aspect ratio will often radically change during mundane conversations, with little rhyme or reason. It switches between 1.90:1 (Digital IMAX), 2.00:1 (Univisium), and 2.39:1 (Widescreen)
- Galaxy Quest used three aspect ratios when it was originally shown in theaters. The opening scene, depicting the Show Within a Show is in 1.33:1 (or 4:3), the standard for TV shows of the time. When it shifts to "the real world", it expands to 1.85:1 (or 16:9-ish). Then when Nesmith gets his first glimpse of the wider universe, and realizes his trip with the Thermians wasn't a game after all, it widens again to 2.39:1 (or Cinemascope). This was simplified for the home video releases, where the Show Within a Show is 1.33:1 and everything else is in 2.39:1.note
- Christopher Nolan likes this trope, due to his frequent use of IMAX: note
- The Dark Knight has a variable aspect ratio. The opening scene where Joker robs a bank is in IMAX, and is followed by scenes in 2.39:1. The Dark Knight Rises switches far more frequently.
- Interstellar has the space scenes in IMAX, and the spaceship scenes in 2.39:1 to emphasize the largeness and grandeur of the former.
- Dunkirk switches aspect ratios a few times between 2.20:1 (standard 70mm) and IMAX.
- The Hunger Games widens the aspect ratio as the fighting begins.
- In The Hunger Games: Catching Fire, the screen goes from 2.39:1 to IMAX when Katniss gets transported to the arena.
- Scott Pilgrim vs. The World switches between 1.85:1 (most scenes) and 2.39:1 (some scenes).
- In Scott's first dream of Ramona in the desert, the screen zooms out to 2.39:1 when he says he's "so alone" to emphasize his isolation.
- In his fight against Matthew Patel, the aspect ratio changes to 2.39:1 as he blocks the latter's first attack to emphasize the moment.
- As with The Wizard of Oz, the prequel film Oz: The Great and Powerful starts out in black and white before switching to color as the main character ends up in the Land of Oz. However, this time the Kansas scenes are also presented in the Academy ratio before switching to Scope as the saturation sets in upon arrival in Oz. The intended effect is lost somewhat on home video as these opening ratios are windowboxed into the 2.35:1 frames the movies eventually expand to.
- Life of Pi goes anywhere from Scope to Academy, but usually it's a (non)square 16:9.
- There's an intermission of sorts in Will Success Spoil Rock Hunter? where Tony Randall appears out of character, talking about film (big screen) vs TV (small screen). The film briefly goes very tiny to show a TV-sized picture.
- At the start of Strange Brew, Bob & Doug McKenzie explain the difference between TV and film by briefly switching to TV, where you can see the scan lines and it's just generally in lower quality.
- TRON: Legacy changes from 2.39:1 to 1.78:1 in some scenes. Also, the movie is filmed in 2D for real-world scenes and 3D for scenes "On The Grid" to further accentuate the computerness of the world.
- The base aspect ratio of Nymphomaniac is 2.39:1, but the ratio changes to 1.85:1 in Chapter 3.
- In The Girl Can't Help It, when Tom introduces the film, he notices the Aspect Ratio is wrong, and then has the camera spread to widescreen.
- The Grand Budapest Hotel changes between three different ratios for the time periods:
- 1.85:1 for scenes set in 1985 to the present day.
- 2.39:1 for the 1960s.
- 1.375:1 for the 1930snote
- (500) Days of Summer has brief Polaroid flashbacks and idealizations in 1:1. There is in fact one scene where the 1:1 aspect ratio is widened and pushed to the side as Tom realizes that his fantasies are hopeless.
- Enchanted begins in a 1.78:1 ratio and switches to a wider one once the story takes off.
- There's a "spread to widescreen" shot in Around the World in 80 Days (1956).
- The World's End does this with film gauge, starting in Super 16mm, then Super 35mm and finally anamorphic 35mm (which is a much larger negative than Super 35 as it doesn't require cropping). The end effect is that the resolution and image quality slowly increases.
- Most of the later films in the Marvel Cinematic Universe contain sequences that have been Specially Formatted In IMAX 1.90:1, mostly during big action sequences.
- Crazy Ex-Girlfriend will change to 4:3 for flashbacks to previous episodes, and will switch to a cinematic aspect ratio for some musical numbers - usually the ones that characters are imagining.
- Black Mirror episode "USS Callister"'s Fake Action Prologue is shot in 4:3, deliberately making it look like an old science fiction show. The rest of the episode is shot in 16:9.
- While Westworld is generally shot in 16:9, some scenes stick out:
- The scenes in episode "Phase Space" with Bernard inside the Cradle as well as his interview with Dolores are shown in a 2.39:1 format with Letterbox, implying that both scenes took place in the Virtual Reality world.
- Also the finale to the second season has scenes within the virtual world "Valley Beyond" shot in 2.39:1.
- Used in Homecoming to indicate which storyline is currently being focused on. The 2018 segments of the plot are filmed in widescreen; for the 2022 segments, the aspect ratio changes to 1:1.
- The original Mass Effect trilogy uses this effect extensively, switching between the native screen aspect ratio during regular gameplay and the cinematic 16:9 during cutscenes and some dialogues.
- Games from the Grand Theft Auto series starting with Grand Theft Auto III switch to a letterbox mode in cutscenes, though Rockstar deprecated this when Grand Theft Auto IV was released, instead using it as a fallback if the game is somehow played on a 4:3 display.
- The Legend of Zelda: The Wind Waker uses a fake 2.39:1 aspect ratio during cutscenes. In cutscenes that transition seamlessly to gameplay, the fake letterbox bars slide off the screen. The game also narrows the screen when L-Targeting is used, but this is closer to Eyedscreen.
- The first 20 seconds of BTS' "Boy With Luv" are in 4:3. Once the song starts, black bars slowly appear from the borders, switching thus into a 16:9 aspect ratio and staying like that for the rest of the music video.
- In general, all of BTS' music videos and short films have the BigHit Entertainment logo in 4:3 while the rest is in 16:9.
- Broken Saints switches in some scenes.
- Strong Bad Email:
Strong Bad: But this particular flashback has way too much historical significance to be shown in anything but WIDESCREEEEEEEEEEEEN!
- In email 100, "flashback", Strong Bad deliberately expands the screen because he thinks this episode is too important for a 4:3 aspect ratio. The wider screen reveals that Homestar Runner is standing right next to him, Behind the Black.
- In "virus", the video is wider than the displayed cartoon, to set up a gag where Strong Bad gets stranded outside the cartoon screen.
- The Mega Man Games episode of The Angry Video Game Nerd shrinks to 4:3 when the nerd travels back to 2007 and reverts back to 16:9 when he returns to the present day.
- One of Homestuck's most climactic Act finales,"Cascade", gets wider as it hits a narrative high point. Cleverly, the outside part of the frame is disguised as the background of the site, so it isn't apparent that the image will get bigger.
- Whenever American Dad! switches to the story arc involving Roger's golden turd, black bars appear above and below the screen to give it a cinematic widescreen feel (this was before the show switched to HD).
- The Family Guy episode "Back to the Pilot" has the ratio go from widescreen to standard when Brian and Stewie go back to 1999.
- In its original 4:3 broadcast, the South Park episode "Good Times With Weapons" switches to a letterboxed 2.39:1 ratio when the boys are engaged in their anime fantasy. When the episode was remastered for HDTV, the switch was eliminated.
- In Avatar: The Last Airbender episode "The Cave of Two Lovers", the aspect ratio changes from 4:3 to 16:9 for when Katara retells the story about the Star-Crossed Lovers Oma and Shu.
- In Teenage Mutant Ninja Turtles (2003), for added drama or to produce a widescreen effect, a black bar will often slide onto the top and bottom of the screen for that shot. Especially prominent in the first season.
- In The Amazing World of Gumball episode "The Test", segments showing the outdated and awful Sitcom starring Tobias are in a 4:3 aspect ratio with film grain.
- In the Steven Universe episode "Joking Victim", the Big Donut Instructional Film VHS is in a 4:3 ratio.