Lumens vs ANSI Lumens: What is the Difference?

Introduction

The selection of a projector depends heavily on brightness levels, yet the distinction between lumens and ANSI lumens remains unclear for most consumers. Both terms can be found in marketing materials, although their standards represent distinct measurement methods. This guide will describe how the two measurement standards differ, provide conversion methods, and help you determine your required brightness level by analyzing StarryHub projector data.

Table of Contents

1. What is Lumens?

The unit of measure for visible light output from a source is lumens. The term lumens exists in lighting products and consumer projectors without any established standard testing procedure. Several manufacturers engage in the practice of publishing inflated lumen ratings on their LED projectors to enhance customers' perception of their brightness.

Lumen values among brands differ substantially because there is no standardized testing process for measuring them. A projector declared at 3000 lumens might deliver significantly reduced brightness when used in real-world settings.

1.1 ANSI Lumens

The American National Standards Institute provides the standardized measurement method for ANSI lumens. This method includes displaying a whie image on the screen, grid partitioning, subsequent brightness measurements from sections, and averaging their results.

The established procedure enables a precise determination of actual brightness with reliable consistency. Professional brands and commercial-grade projectors normally provide ANSI Lumens reports because they help buyers make reliable purchases.

1.2 LED/ Light Source Lumens

Light source lumens refer to the brightness of the projector’s light source. Since this measurement is taken before any light loss through optical components or image processing, the reported values tend to be very high. However, it does not represent the honest brightness on the screen. As a result, the image brightness of such projectors is usually lower than the stated value, making this parameter less useful as a reference.

1.3 ISO  Lumens

Introduced in August 2005, this standard is commonly adopted by Japanese projector brands. It emphasizes a comprehensive testing process that considers factors such as light source power, noise levels, and their impact on brightness. In addition to specifying the size of the projected image, the standard also accounts for projection distance and light loss during operation. As a result, the measurement criteria are more stringent and the overall testing process is more rigorous compared to other methods.

Figure1- conference room brightness 

2. Lumens vs ANSI Lumens: What is the Difference?

A reference table simplifies the comparison between Lumens and ANSI Lumens as shown below. A standardized conversion exists, yet the specific ratio requires consideration of the particular light source type (LED, laser, etc.).

2.1 Why the Difference Matters？

To properly evaluate projectors, see if they provide ANSI Lumens rating information. Using this measurement provides your best opportunity to understand the projected brightness that will appear in your environment.

Although some cheap projectors claim to have 10,000 Lumens, their actual ANSI Lumen values range between 300 and 500 ANSI Lumens. Projectors would show a noticeable decrease in actual performance when light conditions are bright.

Figure2-brightness in dark conference room

3. How to Convert ANSI Lumen and Lumen?

Projector brightness is often listed in ANSI Lumens, LED Lumens, or just Lumens, but these terms don’t all mean the same thing.

ANSI Lumens vs.  LED Lumens

• ANSI Lumens are measured using a standardized method set by the American National Standards Institute. It tests brightness from 9 points on the screen to reflect real viewing conditions.

• LED Lumens or Light Source Lumens are often based on the raw brightness of the light source, not what you see on the screen. These numbers are not standardized and are often exaggerated for marketing.
  

Quick Conversion Guide

The actual situation may vary depending on various factors, and this formula is for reference only:

1 ANSI Lumen ≈ 2.4 LED Lumens

This means:

4. How to Choose the Brightness of Your Projector?

Making the right projector brightness decision does not only involve bigger digits. It all depends on where and how you are planning to use it. Ambient light, screen size, and viewing distance are all things that affect how many ANSI Lumens you need to see a clear picture.

4.1 Key Considerations for Choosing Brightness

When you choose projector brightness, please consider both your affinity with visual clarity and the environment, and the application of the use case. The most important factors to consider are the following:

• Ambient Lighting

The brighter your projector has to be, the more ambient light in the room. A room with many windows or ceilings with lighting that is close to the head, like a classroom, open-plan office, needs a projector with at least 1000-1600 ANSI lumens, to make sure that the image is not washed out under direct sunlight.

Example: Where there is a classroom that has sunlight and fluorescent lights, a projector of 1200–1600 ANSI Lumens will ensure that the images are clear.

• Screen Size

When the screen gets bigger, the amount of brightness has to be increased in order to maintain the vibrancy and readability of the image itself. For a screen greater than 100 inches, a Projector with at least 700–1000 ANSI Lumens will be required for an unbothersome view in rooms without a light source.

Example: For a 120-inch screen in a home theatre set up, choose 800–1000 ANSI Lumens, even in a dark room.

• Projection Distance

As the projector is placed away from the screen, the brighter it gets lost. If your setup needs a large throw distance, make up for it by using the model that has more ANSI Lumens.

Example: In a conference room where the projector is mounted 15 feet from the screen, opt for 700–1000 ANSI Lumens for best visibility.

• Content Type

Text-heavy presentations and detailed visuals require more brightness than movies or casual videos. Projectors used for slideshows, spreadsheets, or training videos should offer 700 ANSI Lumens or more for maximum clarity.

Example: For business presentations with graphs and fine text, a 700+ ANSI Lumens projector is a safe baseline.

Figure3-Ambient Lighting

5. StarryHub Brightness: ANSI Lumens

By the official specifications, StarryHub Q1 Pro provides 2200 ANSI Lumens. The brightness level of this makes the two models appropriate for use in meeting rooms that can hold 5-30 people in meeting rooms with moderate to high levels of background light. These brightness ratings help to keep presentation materials bright and sharp even without a dark room. StarryHub projectors are optimized for business collaboration, hybrid meetings, and video conferencing, maintaining image clarity even in standard office lighting conditions.

Where StarryHub Fits in the Brightness Range

More than a Projector

StarryHub is a smart projector and collaborative meeting device developed by CZUR. Designed as a comprehensive office solution, it combines projection capabilities with a built-in microphone array, speakers, and camera — all seamlessly integrated into a unified operating system, StarryOS.

With features like wireless screen sharing, video conferencing, document collaboration, and support for third-party app installation, StarryHub delivers all the essential tools for professional productivity.

Its all-in-one design and easy setup make it ideal for teams seeking a portable, integrated collaboration solution. Unlike most budget LED projectors, StarryHub strikes a thoughtful balance between image clarity, performance, and usability, making it a practical and powerful choice for modern workplaces.

Figure4-lumens in differen ambient light

Conclusion

When comparing the actual brightness of projectors, it is best to refer to ANSI or ISO lumens, as they accurately reflect the brightness on the screen. Light source lumens should only be used to understand the raw output of the light source and do not represent the final projection brightness. Since ANSI and ISO lumens are nearly equivalent, they can be used interchangeably. If a manufacturer only provides light source lumens or LED lumens, it is recommended to consult third-party test data or reviews to make a more reliable purchasing decision. Additionally, considering ambient lighting conditions, screen size, and usage scenarios will help you choose the projector that best fits your needs.