Project Optional. Used for the PDF report header.
Screen
Seats
Up to 4 rows. Leave a row's distance blank to drop it from the drawing. Eye height auto-fills from the seat type; override per row if needed.
| Row | Distance from screen (mm) | Seat type | Eye height (mm) |
|---|
Targets
Results
Screen and band
Per-row outcomes
How to read this Background on the inputs, drawings, and per-row outcomes.
The two modes
VAC answers either of two questions, depending on what you fill in. Mode A finds the ideal screen width for the seating distance you've supplied. Mode B finds the ideal seating distance for the screen you've supplied. The underlying sightline geometry (top view, side view, riser heights) is produced in both modes.
Sightlines and risers
The side view draws each row's eye position plus the head of the row in front, then traces the sightline that needs to clear that head and still reach the bottom of the screen. Where it doesn't clear, the row needs to be raised — the riser height column shows how much. Recliner seats sit the viewer lower and a little further forward; both factors are reflected in the per-row numbers.
Guideline sources
SMPTE Engineering Guideline 18 specifies 30° as a minimum; THX advises 36° minimum; Dolby's residential recommendation centres on 36°. None of these are absolute — they are considered preferences derived from cinema experience. RP22 viewing-angle ranges and the full RP22 Performance Level evaluation are paid-tier (Cinema Tools Online / Extended).