---
title: "Interlaced Video"
url: https://postproduction.studio/en/glossary/interlaced-video
language: en
description: "Interlaced video is a legacy encoding model where each frame is split into two fields — odd-numbered horizontal lines (the 'upper' field) and even-numbe..."
updated: 2026-10-25
---

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# Interlaced Video

Interlaced video is a legacy encoding model where each frame is split into two fields — odd-numbered horizontal lines (the 'upper' field) and even-numbered horizontal lines (the 'lower' field) — captured at different points in time. The two fields together form one frame, but they sample the scene 1/60 second apart (NTSC) or 1/50 second apart (PAL). The technique was developed in the 1930s for cathode-ray tube broadcasting where the phosphor refresh rate could not sustain a flicker-free image at the full vertical resolution — interlacing effectively doubled the perceived temporal rate while using the same bandwidth as a progressive scan at half the framerate. Modern displays (LCD, OLED) inherently display progressive frames and must deinterlace incoming interlaced content. Interlacing causes visible 'combing' or 'tearing' artifacts when motion occurs between the capture of the two fields, particularly visible on horizontal motion. Modern productions almost universally capture in progressive mode (24p, 25p, 30p, 50p, 60p) avoiding interlacing entirely; legacy SD content (DVDs, older broadcast archives) remains interlaced and requires deinterlacing for modern delivery. The naming convention reflects framerate and field/frame: '1080i 30fps' is 60 fields per second (each frame being two interleaved fields); '1080p 60fps' is 60 progressive frames per second. Reference: ITU-R BT.601 and SMPTE 274M.

Formats, ImageVideo Engineer, Online EditorCapture, Delivery

## Related terms

[Deinterlacing](https://postproduction.studio/en/glossary/deinterlacing)[Progressive Video](https://postproduction.studio/en/glossary/progressive-video)[Frame Rate](https://postproduction.studio/en/glossary/frame-rate)

At 29.97 fps, non-drop timecode drifts ~3.6s ahead of wall-clock per hour. Drop-frame skips 2 frame labels per minute (except every 10th) to compensate.