Frame Rate

Frame Rate

noun | Camera & Optics

The number of individual still images (frames) captured by a camera per second during recording, or displayed by a screen per second during playback. Frame rate is expressed in frames per second (fps) or sometimes Hertz (Hz). It determines the smoothness of motion in the image, the characteristic look of the footage, and the mathematical relationship between shutter speed and motion blur.

Quick Reference

The Explanation: How & Why

A DP on a narrative feature sets the camera to 24fps. The footage looks like cinema. The same DP switches to 60fps for a sports insert. The footage looks like live television. Same camera, same lens, same lighting. The only variable that changed is frame rate, and it transformed the aesthetic entirely. Frame rate is not a technical setting - it is a perceptual one.

The mechanism is temporal sampling. At 24fps, the camera captures 24 discrete snapshots of the scene per second. When played back at the same rate, the human visual system perceives them as continuous motion through the persistence of vision effect. The brain fills the gaps between frames, creating the illusion of fluid movement from a sequence of still images. But the brain also registers the motion blur within each frame, and the amount of blur - determined by the relationship between frame rate and shutter angle - is what produces the characteristic "cinematic" look.

At 24fps with a 180-degree shutter, each frame is exposed for 1/48th of a second. That exposure time is long enough for moving objects to record a visible blur trail within each frame. The brain interprets this blur as motion in time, and the resulting image has a slight dreaminess in movement - a softness that audiences worldwide associate with "movies" rather than "video." At 48fps with a 180-degree shutter (1/96th of a second), each frame contains half the motion blur. The motion is sharper, smoother, and more technically accurate. It also reads as television. The visual system's interpolation finds 48fps too complete to require imagination, producing an image that feels observed rather than experienced.

Higher frame rates capture motion with greater temporal precision. At 120fps, the camera captures five times as many snapshots per second as at 24fps. When played back at 24fps, those 120 frames per second of recording occupy 5 seconds of screen time, producing slow motion at 5x normal speed. When played back at 120fps in real time, the footage appears extremely smooth and detailed, with minimal motion blur between frames.

The HFR (High Frame Rate) debate remains one of the most polarized topics in cinema. Peter Jackson shot The Hobbit trilogy (2012-2014) at 48fps; audiences complained it looked like a soap opera. Ang Lee shot Billy Lynn's Long Halftime Walk (2016) and Gemini Man (2019) at 120fps; the response was similar. James Cameron took a different approach with Avatar: The Way of Water (2022), using TrueCut Motion grading to selectively adjust motion scene by scene rather than applying a uniform HFR. This "cinematic HFR" approach has gained momentum, with films like Godzilla x Kong: The New Empire (2024) and Jurassic World: Rebirth (2025) receiving TrueCut HFR releases, particularly in China's Cinity cinema chain. As of 2026, Western theatrical exhibition remains overwhelmingly 24fps, while China has embraced cinematic HFR as a marketing feature.

To apply this on your next shoot: shoot 23.976fps for theatrical and streaming narrative. Shoot 25fps for European broadcast. Shoot 29.97fps only if North American broadcast is the primary delivery. Use the Slow Motion Calculator to calculate playback speed from capture frame rate, and the Exposure Calculator to recalculate shutter speed when frame rate changes.

Historical Context & Origin

Early silent films were shot and projected at variable frame rates, typically 16 to 20fps, sometimes lower. Hand-cranked cameras produced inconsistent speeds because the operator's cranking rhythm varied. Thomas Edison's early films were shot at approximately 46fps, while the Lumiere Brothers used 16fps. The introduction of synchronized sound in the late 1920s required a standardized frame rate that could anchor a constant audio playback speed. 24fps was adopted as the sound film standard in 1929, chosen as the minimum rate that provided sufficiently smooth motion with acceptable audio quality for optical sound-on-film. Film stock was expensive, and using the lowest acceptable frame rate minimized stock consumption.

25fps was adopted in Europe for compatibility with 50Hz electrical systems and remains the PAL broadcast standard. 29.97fps (approximately 30fps) was adopted for NTSC color television in the United States in the 1950s, with the 0.1% offset from 30fps chosen to maintain compatibility with existing black-and-white television infrastructure while avoiding interference with the color subcarrier. The 23.976fps variant exists for the same reason: 23.976 x 125% = 29.97fps through a 3:2 pulldown process. The 24fps film standard has been maintained through the digital transition and remains the globally accepted frame rate for theatrical cinema, codified in SMPTE ST 428-1.

How It's Used in Practice

Scenario 1 - Narrative Feature (DP, theatrical): The DP sets the ARRI ALEXA 35 to 23.976fps for the entire production. All primary photography is captured at this rate with a 180-degree shutter (1/47.9s exposure). The camera report notes 23.976fps throughout. The resulting footage has the cinematic motion quality appropriate for a theatrical feature. The DCP will be mastered at 24fps for theatrical delivery and at 23.976fps for streaming platforms that require NTSC compatibility.

Scenario 2 - Slow Motion Insert (DP, action film): The script calls for a slow-motion close-up of a glass shattering on a tile floor. The DP switches the Sony VENICE 2 to 120fps and adjusts the shutter to 1/240s (180-degree equivalent). The 120fps recording is played back at 24fps in the edit, producing 5x slow motion. The 180-degree shutter at 120fps preserves natural-looking motion blur in the slowed footage. The DP adds 4 stops of light (two stops for the faster shutter, two stops for the effective ISO loss at high frame rate) to maintain exposure.

Scenario 3 - Sports Documentary (DP, broadcast): A sports documentary requires both real-time interview coverage (25fps for PAL broadcast delivery to BBC Sport) and slow-motion highlight footage (100fps for 4x slow motion at 25fps playback). The DP sets profiles for both rates on the RED V-Raptor and switches between them for different setups. The camera report notes which clips are 25fps (real-time) and which are 100fps (slow-motion intended), so the editor knows to interpret the 100fps clips at 25fps in the timeline.

Usage Examples in Sentences

"We are shooting 23.976fps for the feature and switching to 120fps only for the designated slo-mo inserts."

"At 48fps playback, the audience complained it looked like live television. The HFR look is genuinely controversial."

"24fps is not a limitation. The motion quality it produces is the look the audience associates with cinema."

"Make sure the shutter angle is recalculated when you switch frame rates. 180 degrees at 120fps is not the same shutter speed as 180 degrees at 24fps."

Common Confusions & Misuse

Frame Rate vs. Shutter Speed: Frame rate determines how many frames are captured per second. Shutter speed determines how long each frame is exposed. They are related but independent. At a given frame rate and shutter angle, the shutter speed is calculated from both values: shutter speed = 1 / (frame rate x 360 / shutter angle). At 24fps with a 180-degree shutter, shutter speed is 1/48s. At 120fps with a 180-degree shutter, shutter speed is 1/240s. Changing the frame rate without adjusting the shutter angle automatically changes the shutter speed. Many cinematographers confuse the two when setting up high frame rate cameras, which leads to exposure problems because the faster shutter at high frame rates requires additional light.

Capture Frame Rate vs. Playback Frame Rate: The creative use of frame rate depends on the distinction between capture and playback rates. Slow motion is achieved by capturing at a high frame rate and playing back at a lower one. Real-time footage uses matching capture and playback rates. Some cameras can record at one frame rate and flag the clip for playback at another; others require the edit software to interpret the frame rate. Understanding the intended playback rate before capture is essential for planning slow-motion sequences correctly. A clip captured at 120fps and played back at 24fps produces 5x slow motion. The same clip played back at 120fps produces real-time footage with unusually smooth motion.

23.976fps vs. 24fps: These are not the same frame rate. 23.976fps is the NTSC-compatible variant of 24fps, offset by 0.1% for compatibility with 29.97fps broadcast infrastructure. For native digital streaming and theatrical DCP, 24fps and 23.976fps are effectively interchangeable: most streaming platforms (Netflix, Prime, Max) receive both and display them correctly. But mixing 23.976fps and 24fps footage in the same timeline causes sync drift: over a 90-minute feature, the 0.1% offset accumulates to approximately 5.4 seconds of audio drift. Choose one rate for the entire production and maintain it through delivery.

Variations by Context

Key People & Origin

Peter Jackson (director) pioneered theatrical HFR with The Hobbit: An Unexpected Journey (2012) at 48fps, provoking the "soap opera" debate that continues to shape HFR reception. James Cameron (director) took a different approach with Avatar: The Way of Water (2022), using TrueCut Motion grading to selectively apply 48fps in 3D sequences, which audiences generally embraced. Ang Lee (director) pushed HFR to its extreme with Billy Lynn's Long Halftime Walk (2016) and Gemini Man (2019) at 120fps, though both films struggled commercially. Douglas Trumbull (VFX supervisor, director) conducted the foundational research on frame rate perception through his MAGI process, testing audience responses to frame rates from 24fps to 120fps and finding that immersive qualities peaked between 60fps and 72fps before declining into hyperreality.

Equipment / Tools Reference

Cinema cameras like the ARRI ALEXA 35 support frame rates from 0.5fps to 120fps at 4.6K resolution. The Sony VENICE 2 supports up to 90fps at 4K and 224fps at 2K. The RED V-Raptor supports up to 120fps at 8K and 240fps at 4K. For slow-motion work, specialized cameras like the Phantom Flex 4K capture up to 1,000fps at 4K resolution. On-set monitoring tools like the SmallHD Cine 13 display frame rate and shutter angle in real time. The Slow Motion Calculator and Exposure Calculator on this site calculate playback speed and shutter speed from any capture frame rate.

Standards & Specifications

SMPTE ST 428-1 defines 24fps as the standard theatrical frame rate. The DCI (Digital Cinema Initiatives) specification requires 24fps or 48fps for 2D digital cinema. ATSC A/85 specifies 29.97fps for US broadcast. EBU R128 specifies 25fps for European broadcast. Netflix requires 23.976fps or 24fps for original content delivery, with specific frame rate metadata in the IMF package. The ITU-R BT.2020 standard for UHD broadcasting supports 24fps, 25fps, 30fps, 50fps, and 60fps. Samsung's Onyx LED cinema screens, introduced at CinemaCon 2025, support frame rates up to 4K 120fps, though no mainstream theatrical content has been released at that rate as of 2026.

Common Questions / FAQ

Q: Why is 24fps the cinema standard and not a higher rate?

24fps was adopted in 1929 as the minimum frame rate that produced acceptable sound quality for optical sound-on-film. Film stock was expensive, and using the lowest acceptable rate minimized stock consumption. The motion blur produced by a 180-degree shutter at 24fps (1/48s exposure) became the aesthetic audiences associate with cinema. Higher frame rates produce smoother motion but lose this characteristic look, which is why 24fps has survived through the digital transition despite being technically "slow."

Q: How much light do I need for high frame rate shooting?

At 120fps with a 180-degree shutter, the shutter speed is 1/240s - approximately 2.3 stops faster than 1/48s at 24fps. You need to add roughly 2 stops of light to maintain the same exposure. Some cameras also reduce their effective ISO at high frame rates due to sensor readout limitations, which can require an additional 1-2 stops. Plan for 3-4 stops of additional light when shooting at 120fps compared to 24fps at the same aperture.

Q: Will high frame rate replace 24fps in cinemas?

As of 2026, no. The Western theatrical industry remains committed to 24fps. China has embraced "cinematic HFR" through TrueCut Motion grading, with films like Jurassic World: Rebirth (2025) receiving 48fps releases in Cinity cinemas. Samsung's Onyx LED cinema screens support 4K 120fps, but content availability is minimal. The audience resistance that greeted The Hobbit at 48fps has not been overcome in Western markets, and motion grading rather than uniform HFR appears to be the compromise path forward.

Related Terms

• 24 Frames Per Second - The cinema standard frame rate; the default for theatrical narrative production
• Shutter Speed - Calculated from frame rate and shutter angle; must be adjusted when frame rate changes
• Slow Motion - Achieved by capturing at a higher frame rate than the playback rate
• Overcranking - Running the camera at a higher-than-normal frame rate to produce slow motion in playback
• Undercranking - Running the camera at a lower-than-normal frame rate to produce fast motion in playback

See Also / Tools

The Slow Motion Calculator calculates playback speed and resulting duration from any capture frame rate. The Exposure Calculator recalculates shutter speed when frame rate changes, ensuring correct exposure at any frame rate. For the theory behind frame rate perception and the cinematic look, see the blog post on frame rates in filmmaking.