09-04-2017 02:48 AM - edited 09-04-2017 02:48 AM
I have a (rather technical) question concerning the actual frame rate recorded by the GoPro Hero4 Black. I have put the camera to the setting "720-240", which should indicate 240 fps. The file that is produced has 239 fps listed in the file details when viewed on my computer.
I got curious regarding the actual frame rate and I recorded a shot of a few seconds of an old fluorecent light at the 240 fps setting. Due to the net frequency (50 Hz, as I'm in Europe) the brightness of the lamp is seen to flicker in the video. I used Python to extract the average brightness of each frame to get a brightness-vs-time signal. Then I performed a Fourier transfer over this signal to extract the electrical net frequency. From this I found that the actual frame rate of the video appears to be 300 fps.
So my question: What is the actual frame that the camera records?
I hope there is someone here (maybe from the GoPro technical department) that can shine some light on this?
The settings my GoPro is on are:
- Model: GoPro Hero4 Black
- Video mode at 720px, 240fps
- FOV: N
- Low light: N/A
- Spot meter: off
- ProTune: on
- White balance: 3000K
- Color: Flat
- ISO limit: 1600
- Sharpness: High
- EV comp: -0.5