mcd to Lumens Calculator

Lumens Formula:

\[ \text{Lumens} = \frac{\text{mcd} \times (4\pi \times (1 - \cos(\theta/2)))}{1000} \]

Lumens (lm):

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1. What is an mcd to Lumens Calculator?

Definition: This calculator converts luminous intensity in millicandela (mcd) to luminous flux in lumens (lm) for a given beam angle.

Purpose: It helps lighting designers and engineers convert between these important photometric units.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \text{Lumens} = \frac{\text{mcd} \times (4\pi \times (1 - \cos(\theta/2)))}{1000} \]

Where:

Lumens — Total luminous flux (lm)
mcd — Luminous intensity in millicandela
θ — Beam angle in degrees

Explanation: The formula accounts for the angular distribution of light from the source.

3. Importance of mcd to Lumens Conversion

Details: This conversion is essential when designing lighting systems where both intensity and total output need to be considered.

4. Using the Calculator

Tips: Enter the mcd value (must be > 0) and beam angle in degrees (default 30°). The beam angle should typically be between 5° and 180°.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between mcd and lumens?
A: mcd measures luminous intensity in a specific direction, while lumens measure total light output in all directions.

Q2: Why does beam angle affect the conversion?
A: A wider beam angle means the same intensity is spread over a larger area, resulting in higher total lumens.

Q3: What's a typical mcd value for LEDs?
A: Common LEDs range from 100 mcd to over 100,000 mcd, depending on type and size.

Q4: How accurate is this conversion?
A: It's mathematically precise for uniform beam distribution, but real-world LEDs may vary slightly.

Q5: When would I need this conversion?
A: When selecting LEDs for applications where total light output (lumens) matters more than directional intensity (mcd).