Purple Shadow Regions In Frame

Shak

n3wb
Jun 6, 2018
7
2
London
An IP camera I've not used for a while appears to have developed an issue with purple "shadows" in predictable but indeterminable places. I've attached a screenshot demonstrating the issue.

It's actually a "hacked" XiaoFang cube camera (one of the first generation of this model), and although I don't expect any warranty (or even a fix) I'm interested in the symptoms from an academic perspective. I've never seen it with this camera (although to be fair I've not really paid attention until now), and I have others (of the same model if not hardware revision) which do not suffer from this.

I can confirm that this isn't an IR cut filter issue (as I can turn that on and off). I believe it's some kind of sensor clipping/exposure issue, but I don't know if it's a software or hardware fault, or even what clips (I can't tell by eye what makes these regions special).

Any ideas?
 

Attachments

  • 2023-04-17_16-13 - purple.png
    2023-04-17_16-13 - purple.png
    447.4 KB · Views: 23
  • Like
Reactions: Mark_M
Have a look at this featured thread: Common issues with camera image
It mentions purple fringing, how it happens and how to solve it.

You're right to think is has relation to the exposure :).
 
  • Like
Reactions: JDreaming and Shak
Many thanks for the link, but the problem persists regardless of saturation settings (ie even when black and white!)
 
Many thanks for the link, but the problem persists regardless of saturation settings (ie even when black and white!)
Move the camera away from direct light or change the camera's angle so you're not getting refracted light.
 
  • Like
Reactions: JDreaming
Well days later and the CMOS seems to have died (confirmed by testing it with another ip cam), so it seems the purple shadows were a symptom of a sensor on its way out (or I was doing something that was slowly killing it).
 
  • Like
Reactions: bigredfish