What does lumen per square foot per steradian measure?

It is a non-SI luminance unit expressing luminous flux per area per solid angle, often used in U.S. customary lighting measurements.

Why is the wavelength 555 nm important for this conversion?

555 nm corresponds to the photopic peak where human visual sensitivity is highest, making measurements at this wavelength relevant for vision-related evaluations.

Can I use this conversion for non-visual spectral radiance?

No, this conversion relies on the human eye sensitivity function and is not appropriate for non-visual spectral analysis.

How to Convert from Lumen/square foot/steradian to Watt/sq. cm/steradian (at 555 nm)

Learn how to convert luminance measurements from lumen per square foot per steradian to watt per square centimeter per steradian at 555 nm. This guide covers key definitions, conversion use cases, limitations, and practical examples for lighting and vision research.

Lumen/square foot/steradian

Watt/sq. cm/steradian (at 555 nm)

Please check your input. It must be a valid numeric value.

Lumen/square foot/steradian to Watt/sq. cm/steradian (at 555 nm) Conversion Table

Lumen/square foot/steradian	Watt/sq. cm/steradian (at 555 nm)

Custom Unit Conversion Table Generator – Instant Printable Conversion Tables

Start Value

Enter the starting number (positive decimal or integer ≥ 0). Example: 0.1, 1, 5.

End Value

Enter the ending number (positive decimal or integer > Start Value). Example: 10, 50, 100.

Interval

Enter the step size (positive decimal > 0 and < End Value – Start Value). Example: 1.0, 2.5.

Lumen/square foot/steradian to Watt/sq. cm/steradian (at 555 nm) Conversion Table
Lumen/square foot/steradian	Watt/sq. cm/steradian (at 555 nm)

Explore More Luminance Units Converter

What Is This Tool?

This converter transforms luminance values measured in lumen per square foot per steradian, a non-SI unit commonly used in the U.S., into watt per square centimeter per steradian at 555 nm, a radiometric measure aligned with human photopic vision sensitivity.

How to Use This Tool?

Enter the luminance value in lumen per square foot per steradian
Select the desired output unit as watt per square centimeter per steradian at 555 nm
Calculate to get the converted spectral radiance value

Key Features

Converts non-SI luminance units (lumen/sq. foot/steradian) to radiometric spectral radiance units at 555 nm
Facilitates calibration and comparison between photometric and radiometric measurements
Usable for lighting design, vision research, and optical metrology at the photopic peak wavelength

Examples

10 lumen/square foot/steradian converts to 0.000015759751708199 watt/sq. cm/steradian (at 555 nm)
100 lumen/square foot/steradian converts to 0.00015759751708199 watt/sq. cm/steradian (at 555 nm)

Common Use Cases

Measuring brightness in architectural and lighting projects using U.S. customary units
Calibrating photometers or luminance meters reporting in lumen/sq. foot/steradian to radiometric units
Comparing LED, lamp, or optical output at 555 nm in optical metrology and photometric testing

Tips & Best Practices

Ensure input luminance values are specified in lumen per square foot per steradian
Use the converter at the 555 nm wavelength for relevance to human visual sensitivity
Apply conversion carefully when integrating non-SI units with SI-based measurement systems

Limitations

Conversion is valid only at the 555 nm wavelength and accuracy reduces beyond this spectral region
Assumes human eye sensitivity, thus not suitable for non-visual spectral analysis
Incorporates non-SI units which may need careful handling in SI-based workflows

Frequently Asked Questions

What does lumen per square foot per steradian measure?: It is a non-SI luminance unit expressing luminous flux per area per solid angle, often used in U.S. customary lighting measurements.
Why is the wavelength 555 nm important for this conversion?: 555 nm corresponds to the photopic peak where human visual sensitivity is highest, making measurements at this wavelength relevant for vision-related evaluations.
Can I use this conversion for non-visual spectral radiance?: No, this conversion relies on the human eye sensitivity function and is not appropriate for non-visual spectral analysis.

Key Terminology

Lumen/square foot/steradian: A non-SI luminance unit representing luminous flux per unit area per unit solid angle, equivalent to candelas per square foot.
Watt/sq. cm/steradian (at 555 nm): A radiometric spectral radiance measure of radiant power per unit area per unit solid angle at the 555 nm wavelength.
Photopic peak: The wavelength at 555 nm where human visual sensitivity is at its maximum under well-lit conditions.

Quick Knowledge Check

What units does the converter transform from?

Watt per square centimeter per steradian at 555 nm

Lumen per square foot per steradian

Candela per square meter

At which wavelength is the conversion specifically applicable?

700 nm

555 nm

450 nm

What is a common use case for converting from lumen/square foot/steradian to watt/sq. cm/steradian?

Non-visual spectral analysis

Calibration of photometric and radiometric instruments

Measuring sound intensity

Share Us

Similar Calculators

Online Temperature Interval Units Converter Online Temperature Units Converter Online Heat Flux Density Units Converter Online Volume Dry Units Converter Online Heat Density Units Converter