While looking at some of the many light-emitting devices, such as televisions, LCDs, or light bulbs, you've probably noticed they're not all the same. Some are dim, while others are very bright, and often times you can even adjust the brightness or luminance settings. Display manufacturers use different units and specifications such as nits, lumens, luminance, brightness, or light output to describe their product's light-emitting properties, so it's essential to understand what they're talking about before making a purchasing decision.

Why Understanding Light Measurements Matters in Display Design

Brightness isn’t a one-size-fits-all metric. What looks clear in a dim environment may fade or wash out under direct sunlight. That’s why display performance depends on understanding how light is measured, and how those measurements apply to real-world conditions.

Terms like nits, lumens, and luminance are often used interchangeably, but each serves a different purpose. Knowing the difference between nits vs lumens provides a more accurate path to selecting the right display from the start.

Conceptos de luz

Antes de comparar las unidades de medida de la luz, es esencial entender algunos conceptos:

• Iluminancia: La cantidad de luz que incide sobre una superficie. (lo iluminada que está esa superficie)
• Luminancia: La cantidad percibida de luz emitida por un objeto. La luminancia también se denomina brillo.
• Lumen: cantidad total de luz visible emitida por una fuente luminosa. Es la unidad para medir el flujo luminoso.
• Flujo luminoso (Lux): La cantidad de luz emitida en cada dirección y medida en lúmenes.
• Intensidad luminosa: Cantidad de luz visible emitida por una fuente en una dirección determinada por unidad de ángulo sólido. La candela es la unidad del SI para la intensidad luminosa.
• Candela: unidad de medida de la intensidad luminosa. Una candela mide la cantidad de intensidad luminosa de cualquier punto en una sola dirección.

La luz de una vela equivale aproximadamente a una candela. Algunas de las candelas más altas se dan en focos o láseres, ya que la mayor parte de su luz se concentra en una dirección.

Más información: Tipos de LCD

Unidades de medida de la luz

Podemos medir la luz en función de la luminosidad que percibe el ojo humano. Las unidades más utilizadas para medir la luz son el Lumen, el Lux y la Candela.

Luz Sistema Internacional de Unidades (SI)

Nits

What are Nits? Nits (or NITS) are a measure of luminance, meaning it measures how much light an object emits. The term nit comes from the Latin word nitere, which means "to shine". The nit doesn't officially belong to the International System of Units (SI) or any other measurement system. 

Un NIT equivale a una Candela por metro cuadrado. No sólo representan el mismo tipo de cantidad, sino que también son unidades equivalentes.

Average consumer LCD displays have a luminance of 200 to 350 nits. For LCD displays used outside, 400-700 nits are minimum for use in daylight conditions, and at least 1000 nits to view in bright, direct sunlight. We sell Sunlight Readable displays and IPS displays designed with high-brightness LED backlights for outdoor applications.

How Nits Affect Real-World Display Performance

Nits measure luminance, or the brightness emitted from a display’s surface in a specific direction. This directly impacts how well the screen can be seen in different lighting conditions. A display may appear bright indoors but lose visibility in environments with strong ambient light if the nit level is too low.

For most indoor applications, 250 to 400 nits is usually sufficient. In outdoor or high-glare settings, displays typically require 700 nits or more to maintain legibility. Industrial controls, medical equipment, and automotive interfaces often fall into this higher range.

Lúmenes

El lumen (lm) es la unidad de medida del flujo luminoso en el Sistema Internacional de Unidades (SI). El flujo luminoso es una medida de la cantidad de luz emitida por una fuente medida en lúmenes. Los lúmenes se utilizan habitualmente en las especificaciones de las bombillas para describir la intensidad de la luz. La potencia luminosa de un proyector también suele medirse en lúmenes.

Lúmenes frente a candelas

Los lúmenes describen la potencia luminosa total en todas las direcciones y la candela describe la potencia o intensidad luminosa de un punto específico en una única dirección.

Nits frente a lúmenes

Although both the Nit and the Lumen are units used to measure light output, the key distinction between the two is that the Nit measures luminance or brightness of an object, and lumens measure how much light is being emitted.

Candela contra Nits

1 Candela equivale a 1 Nit. Aparte del nombre, no hay ninguna diferencia entre Candela y Nits.

Luminancia

La luminancia (Lv) mide la cantidad de luz emitida, reflejada o que atraviesa un objeto. La luminancia se mide en candelas por metro cuadrado (cd/m²).

Although there are various units of measurement for luminance, including the Nit (nt) and the foot-lambert (fl), the International System of Units (SI) specifies the candela/square meter (cd/m²) as the measuring unit for luminance.

Related: Image Burn-in

Misconceptions About Brightness and Display Quality

Brightness is often used as a shorthand for display quality, but that can lead to incorrect assumptions. Here are some common misconceptions:

• Higher brightness always means better visibility: Not always. A display rated at 1000 nits might look washed out if contrast is poor or if glare isn't managed. In some cases, a lower-brightness display with optical enhancements will perform better.

• Boosting nits solves all outdoor readability issues: Brightness is just one piece. Optical bonding, anti-reflective coatings, and panel type (like IPS vs standard TFT) all affect how readable a display is in bright conditions.

• Lumens and nits can be compared directly: Lumens measure total light output from a source. Nits measure how bright a display surface appears to the viewer. These are separate measurements used in different contexts. In displays, nits vs lumens is not an apples-to-apples comparison.
• All high-brightness displays behave the same in the field: Two displays with the same nit rating can still look very different. Factors like color accuracy, viewing angle, and ambient light handling influence real-world performance.

Choosing the Right Brightness for Your Application

Lighting conditions play a major role in display performance. Brightness levels that perform well indoors may not be visible in high-glare outdoor conditions.

• Indoor use: In environments like test stations, lab instruments, or control rooms, 250 to 400 nits is usually sufficient. The goal here is comfort and clarity without unnecessary intensity.
• Mixed lighting or partial sun: For equipment exposed to overhead lights, windows, or indirect sunlight, displays in the 400 to 700 nit range offer improved readability without excessive power draw.
• Direct sunlight or harsh glare: Displays used outside or in high-glare areas need to be at least 700 nits to remain legible. This is common in automotive, marine, and industrial field equipment.

Preguntas frecuentes

¿En qué se mide la luminancia?

Candela por metro cuadrado (cd/m²).

¿Cuál es la diferencia entre flujo luminoso e intensidad luminosa?

El flujo luminoso mide la cantidad total de luz emitida por una fuente luminosa en todo su espectro angular. En cambio, la intensidad luminosa mide la luz emitida por una fuente luminosa en una dirección determinada.

¿Cuál es la diferencia entre luminancia e iluminancia?

La luminancia es la cantidad de luz emitida por la fuente y la iluminancia es la cantidad de luz que incide sobre una superficie.

¿Es lo mismo brillo que luminancia?

El brillo no es lo mismo que la luminancia y no tiene una medida cuantitativa. El brillo es una percepción y se suele expresar en porcentajes.

¿Cómo convertir nits en lúmenes?

1 Nit = 3,426 Lúmenes. Para convertir nits a lúmenes simplemente multiplique el número de Nits por 3,426.

¿Cómo convertir lúmenes en Nits?

Divide el número de lúmenes por 3,426.

Conclusión

Understanding the nits, lumens, and luminance specifications is an important factor when choosing light-emitting devices such as LCD screens. However, there are other specifications to consider, such as refresh rate, interface, viewing angle, and resolution. Reach out to one of our engineers today to help you choose the perfect display for your application.