Stray light is an always-occurring phenomenon in optical devices. It describes light scattered and reflected from surfaces inside and outside the device, resulting in unwanted images on the sensor. In sum, this leads to an additional signal on the sensor that does not originate from the source but is wrongly assigned to it.
TechnoTeam has decades of experience in measuring high-contrast images in both product development and production. By developing innovative calibration methods, stray light models and correction algorithms, we have been able to reduce the effects of stray light significantly.
CIE244:2021 publishes the results of these efforts. This document contains the definition of several quality indices for characterizing camera systems. Customers can use such indices to compare systems. For example, the new quality indices f23, f24 and f25, deal with contrast in camera systems.

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Shutter LED

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Automotive headlight

Description Standard system High-contrast system
f23 Effect of surrounding field 1:1 000 1:2 000
f24 Stray light influence for negative contrast 1:100 1:2 000
f25 Edge function 1:1 500 1:15 000

1 according to CIE244:2021
2 requires an advanced calibration