Illumination by Lambert Cosine Law Calculator

✖Luminous intensity is a measure of the amount of light emitted by a light source in a specific direction. It quantifies the brightness or concentration of light in that direction.ⓘ Luminous Intensity [I_v]			+10% -10%
✖The illumination angle refers to the angle at which light is emitted from a light source and spreads over a surface.ⓘ Illumination Angle [θ]			+10% -10%
✖Length of illumination refers to the duration or period of time that a lighting system or light source remains turned on and provides illumination before being switched off or replaced.ⓘ Length of Illumination [L]			+10% -10%

✖Illumination intensity refers to the level or strength of light in a given area. It quantifies the amount of light reaching a surface and is typically measured in units such as lux or foot-candles.ⓘ Illumination by Lambert Cosine Law [E_v]

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Formula

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Illumination by Lambert Cosine Law

Formula

`"E"_{"v"} = ("I"_{"v"}*cos("θ"))/("L"^2)`

Example

`"0.442743lx"=("4.62cd"*cos("65°"))/(("2.1m")^2)`

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Illumination by Lambert Cosine Law Solution

STEP 0: Pre-Calculation Summary

Formula Used

Illumination Intensity = (Luminous Intensity*cos(Illumination Angle))/(Length of Illumination^2)
E_v = (I_v*cos(θ))/(L^2)
This formula uses 1 Functions, 4 Variables

Functions Used

cos - Cosine of an angle is the ratio of the side adjacent to the angle to the hypotenuse of the triangle., cos(Angle)

Variables Used

Illumination Intensity - (Measured in Lux) - Illumination intensity refers to the level or strength of light in a given area. It quantifies the amount of light reaching a surface and is typically measured in units such as lux or foot-candles.
Luminous Intensity - (Measured in Candela) - Luminous intensity is a measure of the amount of light emitted by a light source in a specific direction. It quantifies the brightness or concentration of light in that direction.
Illumination Angle - (Measured in Radian) - The illumination angle refers to the angle at which light is emitted from a light source and spreads over a surface.
Length of Illumination - (Measured in Meter) - Length of illumination refers to the duration or period of time that a lighting system or light source remains turned on and provides illumination before being switched off or replaced.

STEP 1: Convert Input(s) to Base Unit

Luminous Intensity: 4.62 Candela --> 4.62 Candela No Conversion Required
Illumination Angle: 65 Degree --> 1.1344640137961 Radian (Check conversion here)
Length of Illumination: 2.1 Meter --> 2.1 Meter No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

E_v = (I_v*cos(θ))/(L^2) --> (4.62*cos(1.1344640137961))/(2.1^2)

Evaluating ... ...

E_v = 0.442742940871412

STEP 3: Convert Result to Output's Unit

0.442742940871412 Lux --> No Conversion Required

FINAL ANSWER

0.442742940871412 ≈ 0.442743 Lux <-- Illumination Intensity

(Calculation completed in 00.004 seconds)

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Home » Engineering » Electrical » Utilization of Electrical Energy » Illumination » Laws of Illumination » Illumination by Lambert Cosine Law

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Created by Prahalad Singh

Jaipur Engineering College and Research Centre (JECRC), Jaipur

Prahalad Singh has created this Calculator and 100+ more calculators!

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National Institute Of Technology (NIT), Hamirpur

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< 7 Laws of Illumination Calculators

Beer-Lambert Law

Go Intensity of Transmitted Light = Intensity of Light Entering the Material*exp(-Absorption per Concentration Coefficient*Concentration of Absorption Material*Path Length)

Fresnel's Law of Reflection

Go Reflection Loss = (Refractive Index of Medium 2-Refractive Index of Medium 1)^2/(Refractive Index of Medium 2+Refractive Index of Medium 1)^2

Refracted Angle using Snell's Law

Go Refracted Angle = arcsinh((Refractive Index of Medium 1*sin(Incident Angle))/(Refractive Index of Medium 2))

Incident Angle using Snell's Law

Go Incident Angle = arcsinh((Refractive Index of Medium 2*sin(Refracted Angle))/(Refractive Index of Medium 1))

Illumination by Lambert Cosine Law

Go Illumination Intensity = (Luminous Intensity*cos(Illumination Angle))/(Length of Illumination^2)

Lambert's Cosine Law

Go Illuminance at Angle of Incidence = Illumination Intensity*cos(Incident Angle)

Inverse Square Law

Go Luminance = Intensity of Transmitted Light/Distance^2

< 16 Advanced Illumination Calculators

Beer-Lambert Law

Go Intensity of Transmitted Light = Intensity of Light Entering the Material*exp(-Absorption per Concentration Coefficient*Concentration of Absorption Material*Path Length)

Fresnel's Law of Reflection

Go Reflection Loss = (Refractive Index of Medium 2-Refractive Index of Medium 1)^2/(Refractive Index of Medium 2+Refractive Index of Medium 1)^2

Refracted Angle using Snell's Law

Go Refracted Angle = arcsinh((Refractive Index of Medium 1*sin(Incident Angle))/(Refractive Index of Medium 2))

Incident Angle using Snell's Law

Go Incident Angle = arcsinh((Refractive Index of Medium 2*sin(Refracted Angle))/(Refractive Index of Medium 1))

Intensity of Light Transmitted

Go Intensity of Transmitted Light = Intensity of Light Entering the Material*exp(-Absorption Coefficient*Path Length)

Illumination by Lambert Cosine Law

Go Illumination Intensity = (Luminous Intensity*cos(Illumination Angle))/(Length of Illumination^2)

Number of Floodlighting Units

Go Number of Floodlighting Units = (Area to be Lighted*Illumination Intensity)/(0.7*Lumen Flux)

Lambert's Cosine Law

Go Illuminance at Angle of Incidence = Illumination Intensity*cos(Incident Angle)

Spectral Transmission Factor

Go Spectral Transmission Factor = Transmitted Spectral Emission/Spectral Irradiation

Spectral Reflection Factor

Go Spectral Reflection Factor = Reflected Spectral Emission/Spectral Irradiation

Utilization Factor of Electrical Energy

Go Utilization Factor = Lumen Reaching Working Plane/Lumen Emitting from Source

Spectral Luminous Efficacy

Go Spectral Luminous Efficacy = Maximum Sensitivity*Photopic Efficiency Value

Inverse Square Law

Go Luminance = Intensity of Transmitted Light/Distance^2

Specific Consumption

Go Specific Consumption = (2*Input Power)/Candle Power

Luminance for Lambertian Surfaces

Go Luminance = Illumination Intensity/pi

Luminous Intensity

Go Luminous Intensity = Lumen/Solid Angle

Illumination by Lambert Cosine Law Formula

Illumination Intensity = (Luminous Intensity*cos(Illumination Angle))/(Length of Illumination^2)
E_v = (I_v*cos(θ))/(L^2)

What is illumination unit?

Lux, a unit of illumination in the International System of Units (SI). One lux is the amount of illumination provided when one lumen is evenly distributed over an area of one square metre.

How to Calculate Illumination by Lambert Cosine Law?

Illumination by Lambert Cosine Law calculator uses Illumination Intensity = (Luminous Intensity*cos(Illumination Angle))/(Length of Illumination^2) to calculate the Illumination Intensity, Illumination by Lambert Cosine Law is a fundamental principle in photometry and lighting that describes the relationship between the illumination of a surface and the angle of incidence of light. This law essentially tells us that surfaces appear brighter when they are directly illuminated (θ = 0°) and become progressively darker as the angle of incidence increases (θ approaches 90°). This is because as the angle increases, the light is spread over a larger area, resulting in lower intensity at each point. Illumination Intensity is denoted by E_v symbol.

How to calculate Illumination by Lambert Cosine Law using this online calculator? To use this online calculator for Illumination by Lambert Cosine Law, enter Luminous Intensity (I_v), Illumination Angle (θ) & Length of Illumination (L) and hit the calculate button. Here is how the Illumination by Lambert Cosine Law calculation can be explained with given input values -> 3.641609 = (4.62*cos(1.1344640137961))/(2.1^2).

FAQ

What is Illumination by Lambert Cosine Law?

Illumination by Lambert Cosine Law is a fundamental principle in photometry and lighting that describes the relationship between the illumination of a surface and the angle of incidence of light. This law essentially tells us that surfaces appear brighter when they are directly illuminated (θ = 0°) and become progressively darker as the angle of incidence increases (θ approaches 90°). This is because as the angle increases, the light is spread over a larger area, resulting in lower intensity at each point and is represented as E_v = (I_v*cos(θ))/(L^2) or Illumination Intensity = (Luminous Intensity*cos(Illumination Angle))/(Length of Illumination^2). Luminous intensity is a measure of the amount of light emitted by a light source in a specific direction. It quantifies the brightness or concentration of light in that direction, The illumination angle refers to the angle at which light is emitted from a light source and spreads over a surface & Length of illumination refers to the duration or period of time that a lighting system or light source remains turned on and provides illumination before being switched off or replaced.

How to calculate Illumination by Lambert Cosine Law?

Illumination by Lambert Cosine Law is a fundamental principle in photometry and lighting that describes the relationship between the illumination of a surface and the angle of incidence of light. This law essentially tells us that surfaces appear brighter when they are directly illuminated (θ = 0°) and become progressively darker as the angle of incidence increases (θ approaches 90°). This is because as the angle increases, the light is spread over a larger area, resulting in lower intensity at each point is calculated using Illumination Intensity = (Luminous Intensity*cos(Illumination Angle))/(Length of Illumination^2). To calculate Illumination by Lambert Cosine Law, you need Luminous Intensity (I_v), Illumination Angle (θ) & Length of Illumination (L). With our tool, you need to enter the respective value for Luminous Intensity, Illumination Angle & Length of Illumination and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

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