Basics 10. The language of the lighting desk: scene, chase, fade, HTP and LTP

We have covered the hardware. What is left is the words. Open any lighting program or step behind any desk and you will meet the same concepts: scenes, chases, presets, submasters, fade time, blackout. This is professional jargon shared across the whole industry: learn it once and you will understand SvetoMaster, somebody else’s desk at a venue, and an English-language video on YouTube.

Three storeys: preset, scene, chase

Almost all lighting work is built on three levels. Each one is assembled from the level below.

Fig. 1 — How a show is assembled: preset, scene, chase, playlist

Preset — a stored value for one property. A position called «beam on the singer», a colour called «warm amber», a gobo called «stars». A preset does not switch any light on by itself — it is a building block you use during assembly.

Why it matters: if the fixtures get re-rigged and the «on the singer» position changes, you edit one preset instead of fifty scenes that used that position.

Scene (also cue or look) — a snapshot of the state of the light: which fixtures are on, in what colour, pointing where. This is the basic unit of a show. «Blue wash for the intro», «white light for the host’s speech», «red backlight for the chorus» — all of these are scenes.

Chase — a sequence of scenes or steps that replace one another in a loop at a set tempo. The classic: four fixtures light up one after another, a running wave. A chase has a speed (in BPM or seconds per step) and usually direction modes: forwards, backwards, bounce, random.

Effect — a generator of movement or colour calculated on the fly: a circle for heads, a sine wave, a rainbow spread across fixtures. Unlike a chase, where you set the steps by hand, an effect is described by parameters: shape, size, speed, offset between fixtures.

Playlist (cue list, stack) — the running order: a list of what plays and in what sequence through the evening. Press «next» and the show moves to the following item. In theatre it is the main tool; for a DJ it is a way of not having to think in the middle of a party.

💡 Tip: a handy working pattern for a beginner is 6–10 scenes for different moods, two or three chases and one list that puts them in the order of the event.

How the light moves from one state to another

Fade (transition time) — how many seconds the light takes to move from its current state to a new one. Zero is instant, three seconds is soft and gradual. The same scene with a fade of 0 and a fade of 5 feels completely different: the first is an accent, the second is «breathing».

Crossfade — a gradual transition between two states, usually driven by hand: as one dies away, the other comes up. Physical desks have a pair of A/B faders for this.

GO — the «next item in the running order» command. The button a theatre operator presses on a cue line.

💡 Tip: transition time is the beginner’s most underrated tool. A fast colour change on the beat looks energetic; a smooth three-second transition looks striking. The same set of scenes, given different fades, becomes either a club show or a calm banquet.

Controls every desk has

Term	What it does
Grand Master	Overall intensity of the whole show at once. Pull everything down for a second — this is where
Submaster	A fader controlling the intensity of one group of fixtures or one scene
Flash	An instant-flash button: while held, the fixture or group goes to full
Blackout	Kill everything instantly. An emergency button and an effect at the same time
Freeze	Freeze the picture: everything stays as it is, effects stop
Solo	Keep only what is selected, kill the rest
Mute	The opposite — temporarily switch off what is selected, leaving the rest
Blind	Prepare the next scene without showing it in the room
TAP	Tap the tempo by hand so chases run in time with the music

💡 Tip: blackout is not a way to end a number. A hard cut to black works as an accent, but a smooth fade on the master looks more professional. Keep blackout for when something has gone wrong.

Light and music

Two different mechanisms that beginners often confuse.

BPM (beats per minute) — a tempo set as a number. Chases and effects step exactly in that tempo. You can set it by hand, tap it in with the TAP button, or get it automatically from analysis of the music.

Sound-to-light — the light reacts to the loudness or the bass right now: the beat hits, the light flashes. More immediate and more «alive», but also cruder: it reacts to any loud sound, including a shout into a microphone.

In practice the two are combined: a chase stepping steadily on BPM plus accent flashes from the bass.

HTP and LTP

The pair of letters beginners find most obscure — and at the same time a very simple idea.

Picture this: the «blue wash» scene is holding a fixture at 50 % intensity. And right then you press a flash button that asks the same fixture for 100 %. One number goes into the channel — which one?

Fig. 2 — Two sources writing to one channel: HTP takes the higher value, LTP takes the latest

There are two rules for settling the argument:

HTP (Highest Takes Precedence). The highest of the requested values goes into the channel. It applies to intensity: if the scene asks for 50 % and the flash asks for 100 %, the light gets brighter — which makes sense, since light adds up rather than cancels out.

LTP (Latest Takes Precedence). The value that arrived last goes into the channel. It applies to colour, head position and gobos: if the scene asks for blue and you then call red, the fixture turns red. Nobody wants an «average» of red and blue.

In practice both rules are used at once, virtually everywhere: intensity by HTP, everything else by LTP. Hence the perfectly sensible behaviour you will see every day:

two scenes containing the same fixture give you the intensity of the brighter one;
colour and position are set by whatever you pressed last;
to make a fixture stop obeying an old scene you have to switch that scene off, not «cover» it with a new one.

💡 Tip: if a fixture stubbornly holds a colour you can no longer see anywhere, an old chase or scene is still running somewhere. That is not a glitch — that is LTP doing its job honestly.

Groups: how to stay sane

Once you have more than a dozen fixtures, addressing each one separately becomes impossible. So they are combined into groups: «front», «backlight», «heads», «stage left», «bar». A group is selected with one press, and from then on you work with it as if it were a single fixture.

A good habit is to build your groups right after positioning the fixtures, before you start making scenes. Five minutes at the start saves an hour later.

📍 How this looks in SvetoMaster: all of these concepts carry the same names. Scenes, chases and effects are assembled in the work mode, while live mode is a concert desk: banks of buttons, the grand master, blackout, freeze, solo/mute, blind mode, TAP and overlays such as strobe and fog. The playlist runs the evening’s order on a «next» press, and the merge rule — intensity by HTP, everything else by LTP — works exactly as described above. Fixtures can be combined into your own groups, and one fixture can belong to several groups at once.

Key points

A preset stores one property, a scene is a snapshot of a state, a chase is a sequence of steps, an effect is a movement generator, a playlist is a sequence of chases, scenes and effects, and a hyperlist is a sequence of playlists.
Fade (transition time) changes the feel more than the set of scenes itself.
Grand Master, submaster, flash, blackout, freeze, solo/mute, blind, TAP are the standard controls of any desk.
BPM is tempo as a number, sound-to-light is a reaction to the music right now; the two are combined.
HTP — the higher value wins (intensity); LTP — the latest value wins (colour, position, gobo).
Fixture groups are built before the work starts — it makes control far simpler.

Coming next: we move from theory to the venue. The following lesson is about planning the light in a room: where to rig fixtures, how many you need, how to add up channels and electrical load, and what matters about safe rigging.

Next lessonPlanning the light in a room: layout, channels, power, rigging