High Color-Rendering (Natural-Light) LED Lights

A color machine vision system is used to monitor process quality control, discriminating between fine variations in shade or tint. For example, color verification is critical in pharmaceutical manufacturing to maintain the quality, accuracy, appearance, and safety of a pharmaceutical, such as a pill. Consistency of monitoring the color tint and color shade over time is key to maintaining loyal customers when producing shades of cosmetics. 

Like with every other vision application, the choice of lighting will have a big influence on success. The goal of using High Color-Rendering LED lights is to enable the most realistic color reproduction by simulating the spectral output of sunlight and not emphasizing any wavelength range.

The color camera’s white balance function compensates for the influence of the light source’s color temperature through the emphasis or de-emphasis of certain visible wavelengths when acquiring an image. For instance, the camera’s automatic white balance will compensate for a white LED’s spike in the blue wavelengths. Starting with a high color-rendering index across the light’s output spectrum:

  • May improve the reproduction of color in the image.
  • May improve the ability of the inspection software to distinguish between subtle color variations.
  • Minimizes the influence of the camera’s “white balance” function on the acquired image.

Users peering through microscopes can also benefit from the use of a high color-rendering LED ring lights, available from R.J. Wilson, Inc., to improve manual color interpretation and to relieve eyestrain.

The graphs below include the light spectrums of sunlight, a halogen bulb, a standard white LED, and a high color-rendering LED light. Sunlight contains a relatively even output spectrum, while a typical white LED has a strong blue component (the white LED is often a blue LED with a yellow phosphor coating) and the halogen bulb is stronger in the red, generating significant heat. The natural light LED more closely mimics the spectral output of sunlight, with even output across the visible wavelength range.

Please contact R.J. Wilson, Inc. to discuss whether high color-rendering LEDs can be a benefit to your color imaging process.