Exploring Optical Integrating Sphere: A Brief Summary of a New Approach to Improve Photorealism Accuracy

An optical integrating sphere is an indicative, spherical structure apparatus for measuring light, also known as an integrating sphere, omnidirectional reflectance sphere, or illuminance detector. This article will outline the structure, principle, use and some common practices of photometric integrating spheres.

An optical integrating sphere has a spherical shape and is comprised of optical materials, optical sensors and a metallic plate together with a reflection film. It has an uniformly reflecting surface which uniformly diffuses the outer space and illuminance of scattered light for measurement. The reflected element is specifically designed to uniformly control the distribution of light.

The principle of the optical integrating sphere is that it places a light source inside the spherical material which uniformly diffuses the incoming light, also known as the light source, to the walls of the sphere and reflects it to any one of the light sources locations. During the reflection process, the illuminance level is recognized and measured, giving a reliable result.

The main advantages of the optical integrating sphere are that it can accurately measure the reflection rate of an object surface and can understand the effects of time-based change of reflection rate of the object over the years. Additionally, by obtaining luminance information it can accurately determine the material properties of the illuminated object, such as material type, luminescence etc. It can also accurately measure high reflectance surfaces, which is beneficial for color correction.

Furthermore, the optical integrating sphere effectively eliminates the potential sensitivity difference and accurately measures the reflection rate of small objects or even a fragment surface which is particularly important for color adjustment of items like screens, LCD displays, and labels. Also, the results determined by a photometric integrating sphere can be used for both qualitative and quantitative analysis, therefore it can be applied for application concerning a specific surface reflectance.

An optical integrating sphere is commonly used to measure the radiation energy of different light sources such as visible light, ultraviolet light and infrared light, and is also used to detect and measure lamp performance and color consistency and chroma contrast. Furthermore, it is also used for performance estimation, lighting system design, new product development, laser instrument and sensor radiation measurement, etc.

When using an optical integrating sphere, the light source or photograph needs to be placed inside it in the structure’s specific order to evenly radiate and then measure using the measurement device. This requires a technician to be aware of the internal space of a photometric integrating sphere to ensure even radiation for accuracy in measurements. It is recommended to consider physical environmental components such as temperature, humidity, air flow velocities and intensities to ensure accuracy and precision in measurements are guaranteed under different enviroments before starting a measurement.

In actual practice, the surface of the optical integrating sphere must be wiped with cleaning tools before measurements to prevent fogging. Additionally, the sample position at a 90-degree angle from the frame must be adjusted according to the operating manual to ensure light source characteristics and the accuracy of the reflection film in order to avoid measurement deviation. Lastly, when collecting data, the light source must be operated in sync with illuminance to get a quality, accurate measurement result.

In conclusion, an optical integrating sphere is a tool for measuring the illuminance of different types of light source due to its uniform distribution illuminance measurement and accuracy. It is widely used and professional techniques are necessary to obtain accurate measurements.

Tags：LPCE-2 (LMS-9000)