Units of measurement and terms to qualify horticultural lights. After calculation the result size will be displayed. Lumens, Lux, Candela, PAR, PPF, PPFD, DLI. First select your desired calculation type and then enter the lumen or candela value and the beam angle of your lamp. The calculator helps you to easily convert between candela and lumens as well as lumens and candela. So the lamp with the smaller beam angle has the higher candela value. The luminous intensity of a light source is specified in candela.This is the luminous flux emitted in a specific direction in lumens. In case of two lamps with the same lumen value and different beam angles, the luminous flux is distributed over a different solid angle. The luminous intensity results from the luminous flux related to the solid angle. The unit lumen is used for the total luminous flux in a light beam. But a comparison of these values seems to be difficult, because the luminous intensity additionally is direction-dependent. The candela is related to the lumen and lux units. Candela Lumen Comparisonīoth values are transmission units. Especially for highly directional LED bulbs such as spots or LED recessed spotlights, the luminous intensity is sometimes indicated on the packaging or in the data sheet in addition to the luminous flux. This is the luminous flux emitted in a specific direction in lumens. As I mentioned earlier, HDR and WCG are actually different topics, but they are almost always spoken of together when discussing HDR in general.The luminous intensity of a light source is specified in candela. The Candela is the standard unit for measuring light intensity, whereas the Lux is the standard. We’ll be looking at how all of this impacts HDR in our next discussion, where we’ll also talk about colorimetry and wide color gamut. 2 What is Lux 3 What is Lumen 4 Candela vs Lux vs Lumens What Are The Differences 5 Candela vs Lux vs Lumens How They Relate 6 Factors Affecting The Value Of Candela Vs. Candela, Lux, and Lumen all have complicated relationships. Note that we’ve only discussed measurement of total intensity here, not colorimetry. So there you have it-the fascinating world of light measurement. Just enter the lumens value and apex angle to get the corresponding candela value. To give you a sense of perspective, a sunny day will measure somewhere around 10,000–12,000 nits and a moonlit night, with the moon directly overhead, will measure in the very low single (or even fractional) digits. This is an online calculator to convert lumens to candela. Why do you care? Because if you try to look up the light levels for bright daylight or the moonless night sky, you’ll most likely get values in lux (approximately 25,000 lx and 0.002 lx respectively).Īnd finally, we come to the final metric that we need to understand: Nits! The scientific name for this unit is “candela per square meter” (cd/m), but for some reason, the term “Nit” (nt) has become widely adopted when talking about displays (or screens)-the two terms are interchangeable.

If you had the same 1 lumen over an area of 2 square meters, you would only have 0.5 lux and it would appear half as bright. 1 lux is simply 1 lumen per square meter. This one is very simple: it defines how much luminous flux is spread over a given area.

To show the difference between lumens and candela, let’s go back to the example previously used for candela with the partially obscured light bulb. To put it simply, the lumen rating is how much total visible light is produced by a light source. The next term in our “dictionary of light” is the lux (lx). The lumen (lm) is a measurement of luminous flux, or the total amount of visible light. Why do you care? Because most light sources are commonly labelled with their output in terms of lumens. 1 lumen is defined as 1 cd multiplied by the steradian of the beam for which we’re making the measurement (a sphere has a solid angle of 4P steradians, so a source delivering a uniform 1cd in all directions is emitting 12.57 lumens). Luminous flux is measured in lumens (lm). In other words, it doesn’t include the infrared or ultraviolet spectra, and other wavelengths are weighted by the eye’s sensitivity. This quantity is called “luminous flux” and is analogous to “radiant flux”-the measurement of the total power of electromagnetic radiation-except that it takes into account the eye’s variance in sensitivity to different wavelengths of light. Die Definition lautet: Die Candela, Einheitenzeichen cd, ist die SI-Einheit der Lichtstärke in einer bestimmten Richtung. So now we have to consider the measurement of the perceived power (by the human eye) of light. Die Candela ist dadurch definiert, dass für Licht einer bestimmten Frequenz der Strahlungsfluss (gemessen in Watt) durch einen festen Faktor in den Lichtstrom (gemessen in Lumen) umgerechnet wird.

Lumen candela