Isolated Feeds, Line Cuts and Clean Feeds: What They Mean
A plain-words guide to three terms that come up whenever a multi-camera event is booked for television, and why getting them straight early saves trouble later.
Helen Marsh · · 5 min read
Why the vocabulary matters
When a producer rings to ask for coverage of a stage or a large outdoor event, the first few minutes of the conversation are often spent making sure both sides mean the same thing by the same words. A request for the feed sounds simple, yet it can describe at least three quite different deliverables, and each one changes how many people we send, how much cable goes down and what the broadcaster's control room finally receives.
This is the second article in our look at multi-camera event feeds, and it sets aside the planning questions to explain the terms themselves. Nothing here is secret or clever. It is the everyday language of the trade, and a producer who knows it can write a tighter brief, compare quotations fairly and avoid the awkward discovery on the day that the output was not the one they imagined.
The line cut, in plain words
The line cut is the finished programme picture. A vision mixer sits at a switching desk, watches every camera at once and chooses which one goes out at each moment, following the music, the speaker or the action. What leaves the building is a single stream that already looks like television, with its shot changes in place.
If your programme wants coverage it can broadcast more or less as it arrives, the line cut is what you are asking for. It is also the quickest route, because the editorial decisions are made live by the person at the desk, who has usually read the running order and spoken to the director beforehand about which performers or moments matter most.
- One stream out, with the cuts already made
- Suited to live inserts and same-evening transmission
- Editorial choices are made on the night, so the brief matters
Isolated feeds and why people ask for them
An isolated feed, often shortened to an iso, is the raw picture from one camera, recorded or sent separately and untouched by the switching. If six cameras cover a concert, six isos can exist alongside the line cut, each one showing only what that lens saw for the whole performance.
Producers ask for them when a programme will be edited afterwards. A drummer's close-up that appeared for four seconds in the live cut may suit a documentary insert, and without the iso that footage would simply not exist. The cost is practical rather than mysterious: each recorded camera needs storage, a recording channel and someone to label and hand over the material in an orderly way afterwards.
What a clean feed leaves out
A clean feed is a picture with nothing added on top of it. No captions, no scores, no logos, no lower-third name straps, no on-screen timers. It is the same image, stripped of graphics, so that another broadcaster or another language service can lay its own over the top.
This matters most at events watched by several broadcasters. One may want its name on screen while another wants subtitles in a different language, and neither can use a picture that already carries the first one's branding. When we are asked for a clean feed we keep graphics out of the main output and, if a graphics version is also needed, we send it as a separate path so the clean one stays untouched from end to end.
- No captions, logos or timers burned into the picture
- Lets several broadcasters add their own graphics
- Can run alongside a graphics version on its own path
How the three fit together on a real job
These terms are not alternatives. A single event can produce a line cut for live transmission, a clean version of that cut for a partner broadcaster and a set of isos for editing afterwards, all from the same cameras. What changes from one arrangement to the next is the equipment behind the desk and the number of outputs that have to be monitored and delivered.
That is why we ask early which of the three you need, and in what combination. The answer shapes the crew, the cabling and the hand-off arrangements with the receiving control room. Daniel Okafor's signal team plans the routing around it, so a late change to the list is easier to absorb in the first week than on the afternoon of the event.
Questions worth settling before the day
Before any multi-camera job we find it useful to agree a short list in writing. Which outputs are wanted, and who receives each one? Is the line cut for live transmission or for later editing? Do isos need to be recorded, and who takes custody of the media afterwards? Must any version be free of graphics?
Answering these takes a few minutes by phone or email and removes most of the misunderstandings we see. It also makes quotations easier to compare, since two suppliers pricing against the same list are describing the same work. If a term in a brief or a quotation is unclear to you, ask about it. We would much rather explain it in October than correct an assumption in the middle of a live show.
Line cut, isolated feed and clean feed are three separate deliverables that happen to share a set of cameras. Knowing which you need, and saying so at the start, keeps the crew right-sized, the cabling sensible and the hand-off to the broadcaster uneventful. If you are planning coverage and are unsure which combination suits your programme, send us the running order through the contact page and we will talk it through in plain terms.
More from the newsroom
Before You Book Multi-Camera Coverage: A Planning Checklist
A checklist from our senior camera operator for producers weighing up switched multi-camera coverage of a stage or large event, covering venue, crew, signal path and delivery.
Getting Finished Feeds to Broadcasters Through the Darker Months
As autumn weather sets in, delivery paths need more thought than in summer. Daniel Okafor explains how to choose and test satellite, fibre or secure internet routes before the winter schedule fills
How to Brief a Camera Crew Before a Location Shoot
A practical guide from a senior camera operator on what to send a crew ahead of a news, concert or festival shoot, so the day starts with answers rather than questions.
