Lighting Plot Symbol Key (USITT-style)EasyStagecraft Course · Tier 1B · Module 4 (Reading a Lighting Plot) · v1.0 · the symbols every plot uses, decoded

Why this matters. A lighting plot looks like an alphabet you don't know — until you do. After this sheet, you'll be able to look at any plot + identify every fixture by symbol within 30 seconds. USITT (United States Institute for Theatre Technology) symbols are the international standard; AU plots follow USITT or close variations. Smaller details may vary supplier-to-supplier, but the core symbols below are universal.

Conventional fixtures

Symbol	Fixture	What you'll see on plot
	Source Four / Selecon Pacific profile	Long rectangular body + small circle "lamp" at one end + lead. Most common school fixture symbol.
	Fresnel	Plain circle with crosshair. Often labelled "F" or "FRES".
	PAR can	Circle with concentric inner circle. Sometimes labelled "PAR 64" + wattage.
	Cyc light (asymmetric)	Trapezoid (asymmetric reflector). Used for cyc washes top + bottom.
	Striplight / LED batten	Long horizontal box with cell divisions. Cyc wash unit.
	Followspot	Circle with internal triangle showing beam direction. Usually at auditorium back wall.

LED + intelligent fixtures

Symbol	Fixture	What you'll see on plot
	LED profile (Source Four LED)	Profile body + "LED" letter overlay or shading. Sometimes drawn in solid colour.
	Moving head (spot)	Circle with arrow/triangle indicating beam direction. Often the arrow is angled to show actual aim.
	Moving head (wash)	Circle with diamond/wing-spread shape inside. Wash fixture moves but has wider beam.
	LED PAR (ColorSource PAR)	PAR body with "LED" overlay.

Annotation symbols (what's written next to a fixture)

What you see	What it means
#47 next to a fixture	Dimmer or DMX address number 47 (depends on console — often dimmer number in conventional rigs, DMX address in LED/mover rigs).
(74) in parentheses	Channel number on the console (different from address — channel is how the console refers to the fixture).
L201 or R3202	Gel code (Lee or Rosco).
SF26° or S4-26	Source Four 26-degree lens type (narrow throw).
SF36° or S4-36	Source Four 36-degree lens (medium throw).
SF50° or S4-50	Source Four 50-degree lens (wide throw).
1.2k or 750W	Lamp wattage.
Symbol with circle around it	Identifies a "special" fixture (single-use, not part of a wash).
Symbol with arrow → drawn after	The fixture's aim direction. Used in focus charts.
NC or O/W	No colour / open white — no gel.
+L216 or similar after a gel	Diffusion sheet stacked on top of colour.
Number in a small box (next to a fixture)	Fixture's position number on its bar (1, 2, 3 from one end).

Position labels (bars + bridges)

Label	Means
FOH	Front-of-House bar (in the auditorium, ceiling-mounted).
FOH-1 / FOH-2	Multiple FOH bars (1 closer to stage, 2 further back).
BRIDGE	Auditorium cat-walk bridge (between FOH + stage).
LX1, LX2, LX3	Onstage electrical bars, numbered downstage to upstage.
FOH BAR or FOH BRIDGE	The single FOH position (often used for school theatres with one FOH).
BOOM SR / BOOM SL	Vertical pipes stage-right and stage-left in the wings.
LX1 pos 6	The 6th fixture position on LX1 (counted by convention left-to-right or right-to-left; depends on supplier).
CYC TOP / CYC BOT / GR (ground row)	Cyc lighting positions: top, bottom, or floor-level.
LADDER	Pre-built side-light position hanging from above (alternative to a boom).

Special markings + extras

What you see	What it means
Symbol in red ink or shaded	Late addition to plot (revision after the first draft).
Symbol with an "X" through it	Removed in latest revision.
Symbol with a flag/banner attached	Flagged for production manager attention (often a budget query or focus question).
Two symbols overlapping	Two fixtures on the same hanging point (one above the other, often used for double-duty positions).
Symbol with a numbered tag (G27, G15)	Gel cut number — references the gel cut list.
Diagonal line through fixture from corner to corner	Symbol indicates fixture is rotated 45° or hung at angle.
"P" in parentheses next to a fixture	Practical light — a lamp/lantern visible on stage as a prop.
Asterisk *	Note keyed to the legend or revision notes box.

How to use this symbol key

Print this sheet + keep with the lighting plot.
Hold the symbol key next to the plot.
Identify each unique symbol in the plot's legend box (top-right or bottom-left).
Count the units of each type (count circles, count rectangles, count trapezoids).
Cross-check against the bill of materials (often in the same legend box).
Use the rate card to total the hire cost.

Different suppliers have minor variations in their symbols — but the core shapes (rectangle = profile, circle = fresnel/PAR, trapezoid = cyc, triangle inside circle = moving head, telescope shape = followspot) are universal. After this sheet, you can read any school-musical plot in AU.