Timeline Lagging? Cut on ProRes Intermediates
Every scrub spins the wheel and playback drops frames — the machine is not slow, the footage is. H.264/H.265 are long-GOP codecs: one frame decodes from many neighbors, which editors struggle to do in real time. The professional fix is an all-Intra intermediate like ProRes. Here is when it is worth it and which profile.
Decide if your project needs it
Heavy timelines — multi-track compositing, constant speed ramps, per-frame grading — or older machines gain immediately. A two-minute talking head cut straight from H.264 gains nothing. Intermediates are a productivity tool, not a quality trick: ProRes looks the same as high-bitrate H.264; it is fast in structure, not in pixels.
Choosing among four profiles
The tool offers four ProRes 422 profiles: Proxy, the smallest, as substitute footage on struggling machines; LT for large-project rough cuts; standard 422 as the default balance for most projects; HQ for grading and VFX passes, with a clear size jump. Quality headroom and size both climb from Proxy to HQ.
- Old machine, 4K footage: Proxy
- Regular multi-track editing: standard 422
- Grading or VFX downstream: HQ
Mind the size and the final output
ProRes intermediates run several times the source size, so convert the short segments and hero shots; converting a whole film needs disk planning. Delivery is still H.264/H.265 — intermediates are consumables for the edit, not a delivery format. All processing stays in the browser.