ToolHuts

Praktische Tools für exaktes Arbeiten

Rechner für Projektorhelligkeit & Foot-Lambert

Schätzen Sie die Foot-Lambert-Werte aus gelieferten Lumen, Leinwandgröße und Gain oder berechnen Sie umgekehrt die nötige Lichtleistung.

in
%
fL
Estimated screen brightness41.0fL
Approx. luminance140cd/m²
Screen area42.7ft²
Delivered lumens used1750lm
Rated lumens needed977lm

Funktionsweise

How to use it: enter screen size, rated lumens, an estimated delivered-output percentage, screen gain and your comparison target. This keeps marketing output separate from the lumens assumed to reach the screen.

Formula. Foot-lamberts = delivered lumens x gain / screen area in square feet. Approximate cd/m² = fL x 3.426. Reverse rated lumens also accounts for the entered delivery percentage.

Example. A 2500-lumen projector modeled at 70% output delivers 1750 lumens before screen gain and area are applied.

Beispiel mit aktuellen Eingaben

Das Ergebnis oben verwendet genau diese Werte. Dieser Datensatz wird beim Drucken einbezogen, damit die Ausgabe mit den ursprünglichen Messungen geprüft werden kann.

Screen diagonal
120 in
Aspect width
16
Aspect height
9
Rated lumens
2500
Estimated delivered output
70 %
Screen gain
1
Target brightness
16 fL

Hauptergebnis: Estimated screen brightness: 41.0 fL.

Vor Verwendung des Ergebnisses

  • Measure from the datum or reference edge described by this tool, and do not mix inside, outside and centerline dimensions.
  • Keep inputs in the displayed units and preserve more precision than the final cutting or purchasing tolerance requires.
  • When the result is close to a limit, verify it with a test piece, field measurement, manufacturer drawing or qualified project professional.

Einschränkungen

This is an idealized uniform-screen estimate. Calibration mode, zoom, lamp/laser age, optical losses, screen directionality, ambient light, contrast and measurement position affect the real image. Measure the installed system when brightness matters.

Häufig gestellte Fragen

Why include delivered-output percentage?

Rated maximum output may not match the calibrated picture mode you use. The editable percentage makes that uncertainty explicit.