What is the cause of the blue or purple fringing or contours around the lights of FLEXIDOME IP 3100i IR?

Question

FLEXIDOME IP 3100i IR (NDE-3703-AL)
there are blue contours around the lights (artificial and natural ones)

Answer

The root cause or the blue/ purple fringing observed in the images is primarily due to the lens's chromatic aberration, this lens's optical characteristics. This optical characteristic causes different wavelengths of light (such as red, green, and blue) to focus on slightly different positions. As a result, in high-contrast areas, the misalignment between the red and blue channels compared to the green channel leads to the appearance of blue/ purple fringes.

This is a known optical phenomenon that typically occurs under intense lighting conditions. It results from a combination of current hardware design (lens and sensor) caused by strong illumination. Under high-intensity light sources, such effects may appear and are not unique to this specific model—other models with similar optical designs may also exhibit similar behavior in comparable environments.

The phenomenon is due to inherent physical limitations of the current lens and sensor configuration and cannot be fundamentally resolved through firmware or parameter tuning.

This optical behavior is inherently unavoidable under the current hardware configuration.

Solution:

If you are experiencing blue/ purple fringing and would like to reduce its impact, one possible approach is to turn off HDR (Camera > Enhance > High Dynamic Range > Off).

Disabling HDR may help reduce blue fringing artifacts in some scenes, especially when there are strong contrasts. However, please note this may help, but it will reduce the camera’s HDR performance, which could affect overall image performance in challenging lighting conditions.