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Lesson 5 of 7Video Production
Unit 3 · Lesson 5 of 7

Post-Production: Editing, Colour and Export

Assembling the footage into a story, the cuts and transitions that hold it together, correcting and grading the colour, and exporting to the right specification.

5 min read10 practice questionsAsk AI about this →

Key things to remember

  1. 1A non-linear editor references source files rather than containing them, so moving or renaming footage breaks the link.
  2. 2Trimming is non-destructive — the source file is never altered.
  3. 3Straight cuts should be the overwhelming majority of any edit.
  4. 4A J-cut brings the next shot's audio in early; an L-cut carries the current audio over the next picture.
  5. 5Cutting on action hides the join, because the eye is following the movement.
  6. 6The 180-degree rule keeps the camera on one side of the line so screen direction stays consistent.
  7. 7Colour correction fixes and matches; colour grading applies a creative look. Correct first.
  8. 8Codec is the compression (H.264); container is the wrapper (MP4). They are not the same thing.
  9. 9
  10. 10Export each delivery version from the master, never from another export.

Editing is where a video is actually written. The same footage can be cut into something tense, funny or dull, and nothing about that is determined by what was shot — only by what is selected, what order it is in, and exactly when each cut happens.

The non-linear editor

A timeline is layers in time — video stacks up, audio runs below0:000:050:100:150:20V2titlesV1main videoA1dialogueA2musictitleshot Ashot Bshot Cmusic bedSource media for shot B:handleused in the edithandleThe top video track covers whatever is under it. Audio is independent of picture — andwithout handles either side of a clip there are no spare frames to build a dissolve from.
Fig 1A timeline: video tracks stacked above, audio below, and everything editable in any order.

A non-linear editor (NLE) lets you change any part of the sequence at any time without re-doing what follows. It works by reference — the timeline points at your source files rather than containing them, which is why moving or renaming a clip breaks the link and produces 'media offline'.

  • The timeline runs left to right, with video tracks stacked upward and audio tracks below.
  • Trimming adjusts a clip's in and out points. Non-destructive: the source file is never altered.
  • Ripple edit — removing a section and closing the gap, so everything after it shifts earlier.
  • Roll edit — moving the cut point between two clips without changing the total duration.
  • Rough cut is the first assembly; fine cut refines the timing; picture lock means no further changes, so sound and colour work can safely begin.
Organize before you edit
Keep footage, audio, graphics and the project file in one clearly named folder structure, and never move or rename source files once a project references them. A broken link costs more time than the edit it interrupts, and 'media offline' the night before a deadline is a genuinely common way for student projects to fail.

Cuts and transitions

Unlocking sound from picture is what makes an edit feel continuouspicture cutStraight cutpicture and sound change on the very same frameVAshot Ashot BJ-cutthe next scene’s sound arrives first — we hear it comingVAshot Ashot BL-cutthe old sound runs on over the new picture — reactions stay aliveVAshot Ashot Baudio Aaudio Baudio Aearlyaudio Baudio Alingersaudio BBoth names come from the shape the clips make on the timeline once you drag the audio edge.
Fig 2The straight cut does most of the work. Everything else is used sparingly.
TypeWhat it doesWhen to use it
Straight cutAn instant change from one shot to the nextThe default — the overwhelming majority of every edit
J-cutAudio from the next shot starts before its pictureSmooths dialogue and conversation
L-cutAudio from the current shot continues over the next pictureKeeps a reaction visible while someone speaks
Cross dissolveOne shot fades into the nextA passage of time, or a change of place
Fade in / outTo or from blackBeginnings and endings
Match cutCuts on a matching shape or movementConnecting two ideas visually
Jump cutTwo near-identical angles joinedUsually an error; deliberate in vlogs and montage
If a transition is noticed, it was probably wrong
Straight cuts should be the overwhelming majority of any edit. Spin, star-wipe and page-peel transitions call attention to the editing software rather than the story. The rule professionals use: a transition should mean something — a dissolve says time passed — or it should not be there.
  • Cut on action. Cutting partway through a movement — a door opening, a head turning — hides the join, because the eye is following the motion rather than the frame.
  • The 180-degree rule. Keep the camera on one side of an imaginary line through the subjects, so screen direction stays consistent. Crossing it makes two people appear to face the same way.
  • Pace carries emotion. Short shots build energy and tension; long shots create calm and let a moment land.
  • Cut for the audience, not for your footage. A shot you worked hard for still comes out if it does not earn its place.

Colour correction and colour grading

Two different jobs that people call the same thingCorrection — make the shots matchthree cameras, three castssame white balance and exposureGrading — choose a lookneutralwarmcoldCorrection is objective: skin looks like skin,white looks white, and the shots cut together.Grading is a choice: warm for nostalgia, coldand desaturated for bleak. Same footage.Correct first, grade second, and only once the edit is locked — a look pushed ontomismatched shots just makes the mismatch look deliberate.
Fig 3Correction makes shots match. Grading gives the matched footage a look.
AColour correction
  • Technical: fixing what is wrong
  • Balance exposure, white balance and contrast
  • Goal is footage that looks correct and consistent
  • Make every shot in a scene match
  • Always comes first
BColour grading
  • Creative: giving it a look
  • Teal-and-orange, warm nostalgia, cold thriller
  • Goal is mood and tone
  • Applied across the whole piece for unity
  • Only after correction is finished
Correct first, then grade
Grading footage that has not been corrected bakes the errors into the look. Balance every shot so they match, and only then apply a creative treatment on top. Doing it in the other order means fixing the same problem separately in every single shot.

Export

Work backwards from where it will be watched — the destination fixes everything else.Destination: YouTube, 1080p, watched mostly on phones and laptopsResolution1920 × 1080match the source — never upscale to fill a specFrame ratesame as the shootchanging it has to drop or duplicate framesCodecH.264 (or H.265)how the picture is compressedContainer.mp4the wrapper the player actually opensBitrate10–16 Mbpsthe real quality dial — too low and motion blocksAudioAAC · 48 kHz · 192 kbps48 kHz is the video standard, not 44.1Export one minute as a test before the full render — it costs a minute and saves an hour.
Fig 4Work backwards from the destination, and every setting is decided for you.
SettingWhat it controlsTypical choice
ResolutionPixel dimensions1920 × 1080 (HD) or 3840 × 2160 (4K)
Frame rateFrames per secondMatch the project — never change it at export
CodecHow the video is compressedH.264 for delivery; ProRes or DNxHD for masters
ContainerThe file wrapperMP4 for almost everything online
BitrateData per second8–12 Mb/s for HD; higher for fast motion
AudioSample rate and bitrate48 kHz, 192–320 kb/s AAC
Bits to bytes is a division by 8. Useful for checking a file will fit before you render it.
Codec and container are different things
The codec is how the video is compressed — H.264, H.265, ProRes. The container is the file wrapper that holds the video, audio and metadata together — MP4, MOV, MKV. An MP4 file usually contains H.264 video, but the extension tells you the wrapper, not the compression. This is why two files that both end in .mp4 can behave very differently.
Export once, from the master
Every export re-compresses, and compressing an already-compressed file compounds the damage. Keep a high-quality master and export each delivery version from it — never from another export. Re-uploading a downloaded copy of your own video is the classic way to end up with visible blocking.

Worked examples

Reveal one step at a time and try to beat it to the next line.

Example 1
Calculate the approximate file size of a video exported at .
Example 2
An interview edit feels choppy: every cut is visible, and in one section two people appear to be looking the same way instead of at each other. Diagnose and fix.
Example 3
You have a finished edit and need versions for YouTube and for a classroom projector. Describe the export approach.

Where marks get lost

  • Moving or renaming source files after importing them, which breaks every link in the project.
  • Using decorative transitions instead of straight cuts, which draws attention to the software rather than the story.
  • Cutting between two near-identical angles of the same subject, producing jump cuts.
  • Crossing the 180-degree line, so two people in conversation appear to face the same direction.
  • Grading before correcting, which bakes exposure and white-balance errors into the look.
  • Changing the frame rate at export, which causes frames to be duplicated or dropped.
  • Exporting a delivery file from another delivery file instead of from the master.
  • Confusing codec with container, and assuming every .mp4 behaves the same way.
  • Dividing by 1000 instead of 8 when converting megabits to megabytes.
  • Keeping a shot because it was hard to get, rather than because the edit needs it.

Flashcards 13

Non-linear editor (NLE)
Why does 'media offline' happen?
J-cut
L-cut
+ 9 more

Practice

1
What is the approximate file size, in megabytes, of a video at ?
MB
2
What is a J-cut?
3
Two people in conversation appear to be looking the same way instead of at each other. What rule was broken?
4
Which comes first, colour correction or colour grading?
5
What is the difference between a codec and a container?
6
Why should the overwhelming majority of edits be straight cuts?
7
Why does a project show 'media offline' after files are reorganized?
8
Why is cutting on action less noticeable than cutting on a static frame?
9
Order the post-production stages.
  1. 1Export a master, then each delivery version from it
  2. 2Colour correct so shots match, then grade for look
  3. 3Refine timing into a fine cut, then picture lock
  4. 4Import and organize the footage
  5. 5Assemble a rough cut
10
Match each export setting to what it controls.
Resolution
Codec
Container
Bitrate

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