Getting it right: Why controlled light is so important in machine vision

Getting it right: Why controlled light is so important in machine vision

Introduction

Image courtesy of MBJ Imaging

Importance of Controlled Light in Machine Vision

In machine vision applications, the quality of an image is crucial for accurate analysis and interpretation. Controlled lighting plays a vital role in achieving consistent, high-quality images. Without proper lighting, even the most advanced cameras and algorithms struggle to deliver accurate results.

Overview of the Blog Content

This blog will explore the challenges of ambient light in machine vision, the role of controlled light in image quality, and the different types of controlled light available for machine vision applications. We will also discuss how to choose the right lighting solution for your specific needs and provide guidance on selecting the appropriate light source while balancing cost and performance. Stay tuned to learn more about the importance of controlled light in machine vision and how Scorpion Vision can help you find the perfect solution for your application.

Challenges of Ambient Light in Machine Vision

Clouds and light

Fluctuations and Inconsistency

Ambient light is unpredictable. It can change rapidly due to various factors, such as the time of day, weather conditions, and surrounding environment. These fluctuations make it difficult to maintain consistent lighting conditions for machine vision applications, leading to inconsistent image quality and potentially inaccurate results. Additionally, the lack of control over ambient light can cause unwanted reflections and shadows, further impacting the image quality.

External Influence on Image Quality

External factors, such as nearby light sources or windows, can introduce unwanted variations in lighting conditions. These external influences can cause sudden changes in the image quality, resulting in unreliable data for analysis. For example, a machine vision system set up near a window might experience sudden changes in lighting due to passing clouds or the sun's position throughout the day. This variability makes it difficult to maintain a stable and consistent lighting environment, ultimately affecting the performance of the machine vision system.

The Role of Controlled Light in Image Quality

Pixel Value Improvement

Controlled lighting is essential for improving the pixel values in images captured by machine vision systems. By carefully adjusting the intensity and direction of the light source, you can enhance the contrast between the subject and its background, making it easier for the vision system to differentiate between various elements in the image. This increased contrast results in higher accuracy and better performance of the machine vision system, ultimately leading to more reliable data for analysis and decision-making.

Reduction of Noise and Artefacts

Using controlled lighting can significantly reduce the presence of noise and artefacts in images captured by machine vision systems. Noise, such as graininess or random variations in pixel values, can negatively impact the accuracy and reliability of the machine vision system. By controlling the lighting conditions, you can minimise the presence of noise and artefacts, allowing the system to capture clearer and more accurate images. This ultimately leads to better performance and more reliable results for your machine vision applications.

Types of Controlled Light for Machine Vision

Diffuse Lighting

Diffuse lighting is a type of controlled lighting that evenly distributes light across the subject, minimising shadows and reflections. This is particularly useful for applications that require uniform illumination, such as inspecting shiny or reflective surfaces.

Bar Lighting

Bar light

Bar lighting consists of linear light sources that can be used in various configurations to achieve the desired illumination. They are versatile and can be positioned at different angles to create optimal lighting conditions for a wide range of machine vision applications.

Back Lighting

Back light

Back lighting is a controlled lighting technique where the light source is positioned behind the subject, creating a silhouette effect. This is ideal for applications that require the identification and measurement of object outlines or detection of defects on transparent materials.

Ring Lighting

Ring light for machine vision

Ring lighting involves the use of a circular light source that surrounds the camera lens, providing even illumination on the subject. This type of lighting is suitable for various machine vision applications, including inspection of flat surfaces, texture analysis, and character recognition.

Dome Lighting

Dome light for machine vision

Dome lighting, also known as cloud lighting, creates virtually shadow-free, diffuse illumination from all angles. This is achieved by using a hemispherical light source that evenly distributes light over the subject, making it an excellent choice for inspecting objects with complex geometries or uneven surfaces.

Coaxial Lighting

Coaxial light for machine vision

Coaxial lighting utilises a light source that is aligned with the camera lens, providing even illumination and eliminating shadows and reflections. This type of lighting is particularly useful for applications that involve the inspection of flat, reflective surfaces or materials with fine details.

Horizontal Ring Lighting

Horizontal ring light for machine vision

Horizontal ring lighting features a ring-shaped light source that is positioned horizontally around the subject, providing uniform illumination from multiple angles. This type of lighting is ideal for applications that require inspection of cylindrical or curved objects.

High Power Lighting

High power lighting for machine vision

High power lighting offers intense illumination for applications that require a large amount of light, such as high-speed inspections or imaging tasks with short exposure times. These lights are designed to deliver consistent, bright illumination for accurate and reliable machine vision performance.

Top Lighting

Top lighting for machine vision

Top lighting is a controlled lighting technique where the light source is positioned above the subject, providing direct illumination. This type of lighting is suitable for a wide range of machine vision applications, including surface inspection, defect detection, and dimensional measurement.

Wide Bar Lighting

Wide bar lighting for machine vision

Wide bar lighting is a type of bar lighting that features a larger luminous area, providing more uniform illumination across a wider surface. This makes it ideal for applications that require consistent lighting conditions over large areas, such as web inspection or large object inspection.

How to Choose the Right Lighting Solution

Understanding the Application Requirements

Before selecting a lighting solution, it is essential to understand the specific requirements of your machine vision application. Consider factors such as the size, shape, and surface properties of the objects being inspected, as well as the desired level of image quality and the environmental conditions in which the system will operate. This will help you identify the most suitable type of controlled lighting for your application.

Selecting the Appropriate Light Source

Once you have a clear understanding of your application requirements, you can begin to evaluate the various types of controlled lighting available. Consider the specific advantages and limitations of each lighting technique and how they may align with your application needs. Consulting with an expert in machine vision lighting, such as Scorpion Vision, can also provide valuable guidance in selecting the most appropriate light source.

Balancing Cost and Performance

When choosing a lighting solution, it is important to strike a balance between cost and performance. While high-end lighting options may offer superior performance, they may not always be necessary or cost-effective for your specific application. By carefully evaluating the performance requirements of your machine vision system and considering the various lighting options available, you can find a solution that delivers the desired results without breaking the bank.

Conclusion

Recap of the Importance of Controlled Light in Machine Vision

In conclusion, controlled lighting is a critical component in machine vision applications. It plays a vital role in ensuring consistent image quality, improving pixel values, and reducing noise and artifacts. By understanding the various types of controlled lighting available and carefully considering the specific requirements of your application, you can select the most suitable lighting solution to achieve optimal results.

Encouragement to Contact Scorpion Vision for Expert Advice and Product Selection

If you require assistance in selecting the right controlled lighting solution for your machine vision application, do not hesitate to contact Scorpion Vision. Our team of experts is dedicated to providing professional advice and guidance in choosing the best cameras, lenses, and accessories for your needs. With our commitment to staying up-to-date with industry trends and offering a wide range of products, Scorpion Vision is the ideal partner for your machine vision requirements.

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