Camera Test in the Sun

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Last week we were able to test the GoPro cameras outside to see at what temperature the GoPro cameras fail, especially the top camera that would be directly facing the sun. The high was 83F in the afternoon, with several clouds in the sky. The thermometer cord was attached to the back of the top camera to record its changes in temperature.


Attaching a thermometer to back of GoPro
Inside Payload (Top camera connected to one power bank, side cameras connected to another)

Setting up pole and payload so that the camera can record changes in thermometer.

Results:
38900 Lux of Sun on Roof

Top Camera (#1, Gopro Hero 3+ Black, 720p at 120fps):

98.2F - Initial Thermometer Reading at 10:35AM

116.8F - Thermometer Reading at 11:57AM

108.7F- Thermometer Reading at 1:16PM

36.5GB of memory used, recorded for 2 hours and 52 min (172 min)

Side Camera (#2, GoPro Hero 3+ Silver, 1080p at 60fps):
Temperature data not recorded for this experiment
31.7GB of memory used, recorded for 2 hours and 54 min (174 min)

Side Camera (#3, GoPro Hero 3+Silver, 1080p at 60fps):
Temperature data not recorded for this experiment
28.9GB of memory used, recorded for 2 hours and 54 min (174 min)

Due to looming black rain clouds, the payload was brought back in before the GoPros showed any possible effects of heat. The temperature never reached 125F (which we wanted to test in since that is when the GoPro cameras supposedly shut down according to the official website). We were unable to read the changes in the thermometer screen due to sun flare in the GoPro footage. We can only tell the temperatures for the times we took pictures of the thermometer when we checked outside.

Even after post-processing, the temperature was hard to read from the GoPro 
It seems that recording at higher fps uses more memory, since it is approximately 4.71 minutes per one GB for the top camera (720p at 120fps) compared to 5.49 and 6.02 minutes per one GB for the side cameras (1080p at 60fps).

The temperature of battery post-experiment

The lenses were more heated than the battery. 

While we are waiting on optimal weather conditions to perform experiments, we are researching what causes GoPro cameras to overheat and how to avoid a shutdown. We are contacting other HAB balloons to see if they have ever had any overheating problems. 

So far, possible explanations for the overheating of cameras (main suspect in camera failure) include hot conditions on the ground before launch, positioning the cameras in full sun exposure outside the payload, camera cases that insulate heat, and additional heat generated by charging the cameras while they are recording.

We will redo this experiment on a bright, sunny day hopefully soon (So far mother nature has not cooperating, with cloudy forecast all throughout this week). After that, we will see if covering aluminum foil around the camera lens can increase camera recording.










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