I am recording from 8 raspicams using picamera. Initially the cameras gives the desired output but soon there is purple band/haze which appears on 3 cameras out of 8.

I checked for digital_gain, analog_gain, brightness, contrast, sharpness values through all 8 cameras for each frame and it was consistent across all 8 cameras and all frames in each frame for 1 hr recordings.

One more thing, I am driving these outputs to zmodo multi channel system to check the video output and Zmodo uses PAL scheme.

Here are sample of initial setup frame and post purple haze addition, Trust me the haze is more than the one shown in the image.

The desired output

Post purple haze addition


1 Answer 1


Check your white balance (awb_mode) and exposure times (shutter_speed). Those pictures look like they were taken on a factory floor with Mercury Vapor lights in the rafters. Those lights are terrible for photography. In that case, your best bet is a Fluorescent white balance setting and a longer exposure setting. You could also try adding some task lights over the work area.

  • the awb_mode is off and I have set the awb_gains to 1.7. but like I said, there are 7 other cameras except this which don't have this issue. I will try with flourescent settings anyways and let you know. Thanks! Commented Feb 18, 2016 at 10:23

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