Theatre Angle Calculator – Tilt, Beam & Footprints

Inputs

m / degrees

a) Truss height (m)

b) Actor offset from Z axis (m)

c) Actor centre height (m)

Desired target beam circle diameter D (m)

Enter the desired beam circle diameter at the target. The calculator will derive the required beam angle θ (full angle). Footprints are intersections of the beam cone with the floor plane (z = 0) and the wall plane (x = d).

Results

Height difference Δh (truss − target)

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Tilt below horizontal α

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Angle to vertical β

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Axis distance lamp → target s

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Required beam angle θ (full angle)

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Target beam circle diameter D

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Target beam circle radius R

–

Floor footprint ellipse (major × minor)

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Floor footprint centre (x from Z axis)

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Wall footprint ellipse (major × minor)

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Wall footprint centre height (z)

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Diagram

2D side view (x–z)

The diagram is schematic (2D side view). Numeric ellipse diameters are the accurate outputs.