Hello, has anyone encountered the flickering lights issue? I was filming indoors using the NSTC format, but my video was flickering (seen through my gopro lcd screen), but after I changed to PAL, the flickering was gone. Is this normal??
Flickering in video and film is a common problem resulting from certain frame rate and shutter speed combinations under artificial lighting.
Although light sources might appear continuous to our eyes, many actually illuminate using high frequency pulses of light. Flickering results when the combination of shutter speed and frame rate captures different fractions of these pulses each frame.
Singapore electricity is 230v AC, the AC frequency is 50Hz (pulses at 50Hz cycle or lighting is cycling ON-OFF 50 times per second).
The key is that many types of artificial lighting flicker at twice the rate of the power source. This is most pronounced with fluorescent lighting, but also happens to a lesser extent with incandescent. Common power sources are 50 Hz (in Europe and most of Asia) and 60 Hz (in North America), which cause 100 and 120 pulses of light each second, respectively.
Video format NTSC is 60Hz and PAL is 50Hz, therefore when you use NTSC mode, there is flickering while in PAL, there is none.
Flicker-Free Frame Rate
(equal light each frame)
Flickering Frame Rate
(unequal light each frame)
How to Prevent Flicker in your Video
It all comes down to synchronization. If you synchronize your camera to the electrical frequency of the lighting, you are basically telling your camera to only take pictures of the ON portion of each cycle within the frequency. So how do we do achieve synchronization? There are two options:
1. Change Your Camera’s Frequency Setting (NTSC or PAL)
2. Change your Shutter Speed/Angle
Hope this helps.