Convert Mcd to MicroEinstein - Tips & Hints

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SUMMARY

The discussion focuses on converting luminous intensity measured in millicandelas (mcd) to microEinsteins, specifically for an LED emitting at a wavelength of 660 nm with an intensity of 1500 mcd. It emphasizes the importance of knowing the luminous efficacy of the LED and suggests starting with the power output of the LED for accurate conversion. The conversion involves using Planck's constant to relate watts to Einsteins per second, assuming 100% efficiency and monochromatic light.

PREREQUISITES
  • Understanding of luminous intensity and its units (millicandelas)
  • Knowledge of luminous efficacy and its role in LED performance
  • Familiarity with Planck's constant and its application in photonics
  • Basic principles of light wavelength and its impact on energy calculations
NEXT STEPS
  • Research how to calculate luminous efficacy for different LED types
  • Learn about the relationship between watts and Einsteins using Planck's constant
  • Explore the concept of monochromatic light and its implications in photometry
  • Investigate methods for measuring the power output of LEDs
USEFUL FOR

Engineers, physicists, and lighting designers who need to convert luminous intensity measurements for LED applications, particularly in photometric calculations and energy efficiency assessments.

taupune
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Hi all.

I have been looking around for a while and done quite some research, however i couldn't find an answer. The one I found were quite complicated ones.

My question is of how to convert mcd to microeinstein.
I know it depends on wavelength. I am using LEd with 30deg angle and 1500mcd and near 660 wavelength (red color).

The closest I could get was using info from this website:
http://hyperphysics.phy-astr.gsu.edu/hbase/vision/lumpow.html

however einstein is in /m^2*s.

S how can i transform the watt to einstein?

I just need a close approximation not exact answer.
Could you give some tips/hints?

Thank you
 
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It's tricky, candelas are a perceptual unit, you need to know the luminous efficacy of the LED.

I'd suggest starting at the other end; don't you know the power of the LED? That's usually easier to find out (and I suspect the luminous intensity was calculated from it anyway?. LED's are pretty efficient and pretty monochromatic. So if you assume 100% efficiency and purely monochromatic light, then you should be able to convert watts directly into Einsteins/second using Planck's constant.
 

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