15 perforations · one frame · no compromise
Still: The Odyssey (2026) © Universal Pictures / Syncopy · official 16:9 still trimmed at the sides to 1.43, schematic
An interactive guide to the largest film format ever created — and why it matters in the age of synthetic images.
Today, the vast majority of films are shot digitally. But cinema was born on celluloid — and a handful of directors still choose to shoot on film, not out of nostalgia, but as a deliberate artistic choice.
Film stock comes in different gauges: 8mm (home movies of a bygone era), 16mm (long the format of choice for documentaries and independent cinema), 35mm (the universal cinema standard for nearly a century), and 65/70mm (large format, reserved for a select few epic productions).
And then there is IMAX 15/70mm — the largest motion picture film format ever created.
The name 15/70 is the spec: 70mm film runs sideways through camera and projector, and each frame takes 15 perforations along its length. A single frame is 69.6 × 48.5 mm, 3,376 mm², roughly 10× the area of a standard 35mm frame. This isn't merely “bigger.” It is a different kind of magic — a photochemical reaction between light and silver halide at a scale no other format can match.
Choosing IMAX 15/70mm was never just about shooting on film. It is the pursuit of capturing the physical world with the greatest possible fidelity — because there is no replacement for displacement.
(Technical note: “70mm” is the width of the release print; the camera negative is 65mm. On conventional 70mm prints the extra 5mm carries four magnetic stripes for six-track stereo sound. IMAX prints carry no sound at all — it plays separately; see Chapter 05.)
This is the largest motion picture frame ever created.
No pixel grid. No compression. Just light on silver.
Still: The Odyssey (2026) © Universal Pictures / Syncopy
Still: The Odyssey (2026) © Universal Pictures / Syncopy · official 16:9 still trimmed at the sides to 1.43, schematic
24 frames a second, 71.25 mm a frame. The two strips below are drawn at one scale and run on one clock.
All derived from 71.25 mm × 24 fps. Weight scaled from the published 600 lb Oppenheimer print; approximate.
24 times a second the film has to stop, be lit, and move on one frame. A 35mm projector does it with an intermittent sprocket: a frame is 19 mm, you can yank that. A 15/70 frame is 71 mm and the film runs at 1.7 m a second; yank that and it tears. IMAX’s answer is the rolling loop: don’t pull the film, roll a wave through it.
Once a turn, the pin wheel’s pin drives a Maltese cross a quarter turn: the 16-tooth sprocket on the same shaft moves four teeth and yanks the film down one frame, then stays locked for the other three quarters. A loop of film above and below the gate lets the steadily turning sprockets above and below and the stop-start intermittent sprocket work without pulling on each other. The two-blade shutter closes twice a frame, once over the pull-down and once mid-picture. 24 times a second, all of the force goes through the perforations.
Same camera and same millimetre scale as the rolling loop below. Film, perforations, pictures and the 16-tooth intermittent sprocket are to size; the Maltese cross, pin wheel, shutter, lamp house, lens and the upper and lower sprockets are schematic in size and place, and the casing is left out; the ruler on the base is marked in centimetres. Seen from the lamp side, the picture in the gate is turned half round. Still: The Odyssey (2026) © Universal Pictures / Syncopy
The rotor turns inside a fixed stator, and the film runs between them. The rotor has 8 gaps in its rim; the film dips into each as a loop, and the loops ride round with the rotor. As a loop passes the gate it draws that frame off the glass, moves it on one frame and sets it back on the register pins. The rest of the time the film at the gate is still, with no pull on the perforations. The shutter blades are narrower than the picture: crossing the gate, one hides only the strip where the wave is, with the old frame still showing on one side and the new one on the other, so the screen never goes fully dark.
Same camera and scale as the 35mm drawing above. The rotor (37.5 in, about 95 cm across) and the film are drawn in real millimetres; the rotor’s upper ring and the spider it hangs from are left out so the waves in the film can be seen. The shutter width follows from the 68% figure (16 equal blades, each 7.2° of the rotor); the wave width and every other part’s size and place are schematic; the ruler on the deck is marked in centimetres. Still: The Odyssey (2026) © Universal Pictures / Syncopy
Sources: US patents 3,494,524, 3,600,073, 4,971,435 and 5,587,750, the IMAX technical fact sheet (IEEE archive), in70mm.com, the Ushio product page, the Science Museum, London. Projector mass and size are press figures.
An emulsion does not store a number of pixels. Kodak measures how much contrast survives as the lines get finer: full at 10 cycles a millimetre, about 30% at 80. The curve fades; it never hits a wall. A sensor is the opposite: full contrast up to half its pixel pitch, then nothing true beyond it. So “film equals so many K” is always an estimate, and it depends on where you draw the line.
The stock in a 35mm camera and in a 15/70 camera is the same Vision3. What differs is how many millimetres of it one frame gets. Count at 80 cycles a millimetre, two pixels per cycle: 22 mm gives about 3,500 across; 69.6 mm gives about 11,100. 3.2× linear. That is the whole advantage, and it is real.
Prints: Nolan’s are struck photochemically from the negative (Dunkirk straight from the original, Oppenheimer through a colour internegative). Most other 15/70 prints are recorded from a digital master and cannot exceed it.
11,100 is the emulsion alone, behind a perfect lens. The lens is the first limit: the best large-format glass resolves roughly 8,000 across a 15/70 frame, and IMAX itself scans these negatives at 8K. Nolan’s prints are struck photochemically from the negative; most other 15/70 prints are recorded back from a digital master and cannot exceed it. And the 18K figure? It assumes 130 cycles a millimetre, a number Kodak’s chart does not even reach.
On the 24.1 m screen at CityWalk a 4K pixel is 5.9 mm wide, a 2K pixel 11.8 mm, and the finest detail the film chain delivers about 3 mm. An eye with 20/20 vision separates one arc minute: 2.5 mm from the front row, 6.3 mm from the back. Slide the seat. From most of the room 4K sits at or inside what the eye can resolve; what film adds is visible from the front half.
Sources: Kodak 5207 / 5219 technical data (MTF curves), ARRI Alexa 65 specifications, Pawel Achtel ACS MTF analysis, American Cinematographer on Dunkirk, FotoKem on Oppenheimer, IMAX mastering notes on the DCP-o-matic forum. Sweeps and insets are schematic, not to scale.
In an age of synthetic images,
the grain is the truth.
Fifteen perforations carry a single frame
ten times the area of 35mm —
a window, not a representation.
This site exists because
some things deserve to be witnessed,
not merely watched.
What these frames carry is the history of cinema — and the history of us.
One 15/70 frame, drawn in real millimetres. Every number from the six chapters lives on it.
Still: The Odyssey (2026) © Universal Pictures / Syncopy
18 films · 2008–2026
Every narrative feature ever captured on IMAX 15/70mm film.
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