24p and judder
Whether 24 fps film is shown at an even multiple (48/72/96/120/240 Hz), or with 3:2 pulldown at 60 Hz (judder).
- Standard
- Vendor / measured
- ISO 21118
- Extension
- Status
- Standard reference being re-verified
How to compare it
Native 24p display
Essential for film lovers. The internal app's 24p behaviour is tested separately as `observed.app_24p_correct`.
Internal apps output 24p correctly
Whether built-in streaming apps play film at 24p, or force 60 Hz with judder.
A huge real-world issue with smart projectors that specs never reveal.
Standard: Reviewer
Marketing traps
- Native 24p display: 'Supports 24p' can mean it *accepts* 24p and converts it to 60 internally.
Deep cut
Native 24p display. With 3:2 pulldown, frames alternate between 3 and 2 refreshes (50 and 33 ms at 60 Hz), and that uneven cadence shows on slow pans. Many smart-projector apps output 60 Hz regardless of content.
Terms on this page
24p / 3:2 pulldown / judder
Film is 24 frames/s. A projector that shows 24p at a multiple of 24 Hz (48/72/96/120/144) avoids 3:2 pulldown judder. ⚠ Some smart projectors can't output true 24p from their built-in apps. ⚖ processing.native_24p (bool), observed.app_24p_correct