PAKENHAM ROOM / BRIEF
VIEWING-GEOMETRY RESEARCH NOTE
Reviewed: 23 August 2026

PURPOSE
This note records the external guidance used in the brief. The brief's calculations are deliberately conditional: they must not be treated as a sofa pass/fail until the TV underside and the loaded sofa seat height are measured in millimetres.

TV MODEL
LG OLED83G4PSA / 83-inch OLED evo TV.
Official LG Australia model page:
https://www.lg.com/au/tv-soundbars/oled-evo-tv/oled83g4psa/
Published dimensions without stand: 1,847 mm W × 1,057 mm H × 28 mm D.
The screen-centre calculation is therefore: measured TV underside above finished floor + 528.5 mm.

The supplied LG dimensions screenshot also records:
- TV with stand: 1,847 × 1,115 × 321 mm
- Packaging: 2,050 × 1,210 × 253 mm
- Weight without stand: 40.9 kg
- Weight with stand: 47.5 kg
- Packaging weight: 58.4 kg
- Stand footprint: 501 × 321 mm
- VESA mounting: 400 × 400 mm
The sofa geometry uses the without-stand panel dimensions. The without-stand weight and VESA pattern are retained as wall-mount references; stand and packaging figures are installation / delivery context only.

VIEWING DISTANCE
LG's viewing-distance guide places 76–85-inch 4K screens in an approximate 2.3–2.6 m cinema-distance band. The measured comfort position is 2,650 mm from relaxed seated eyes to the TV wall. With the screen front approximately 63 mm in front of the wall, the equivalent eye-to-screen distance is approximately 2,587 mm. This is the primary placement target; the guide range remains contextual, not a substitute for the measured position.
LG guide:
https://www.lg.com/us/tvs/tv-buying-guide/right-tv-size-for-my-room

FIELD OF VIEW
For the approximately 1,850 mm measured screen width at 2.587 m eye-to-screen distance:
2 × atan((1.850 / 2) / 2.587) = approximately 39.4 degrees horizontal field of view.
The distance is measured from the front face of the screen to the viewer's relaxed eyes, not from the back of the sofa.

VERTICAL LINE OF SIGHT
THX room-setup guidance uses a line of sight near screen centre and a simple approximately 15-degree above/below-screen-centre guardrail. The brief uses that as a plain-language check, not as a building code or ergonomic guarantee.
THX guidance:
https://www.thx.com/room-size/

SEATED EYE REFERENCE
The supplied body measure is approximately 770 mm from the seat surface to relaxed eye level. The current target is 1,170 mm eye height above finished floor, with an acceptable range of 1,160–1,180 mm. Subtracting the supplied body rise produces an arithmetic loaded-seat baseline of approximately 400 mm. That is not a universal sofa requirement or an occupied measurement. In the showroom, sit normally and measure finished floor to the eyes directly.

TV-HEIGHT INPUT
The current decision input is 77.5 cm = 775 mm from finished floor to the lowest visible TV panel edge.
At that input, the calculated screen centre is 775 + 528.5 = 1,303.5 mm above finished floor.
The Stylesmiths elevation shows a separate design baseline of 800 mm to the TV underside. It remains a nominal comparison only; the current 775 mm measurement is the value used by the brief.
If the installer rechecks it, record the result in millimetres and identify the endpoint: finished floor to the lowest visible TV panel edge.

LIMITS
This note does not turn nominal Arden drawing dimensions into as-built measurements. It does not infer cushion compression, usable seat depth, final modular orientation, or a sofa's comfort from catalogue dimensions. Those remain showroom or site checks.