NTSC is the American image standard, and PAL is a European standard. For common use and less experienced users, we recommend using the PAL format.
In the case of artificial electric lighting (for example in the tunnel), the image may flicker and can not be used. For outdoor natural lighting, of course, this problem does not arise.
These standards are based, among other things, on the standard of electrical voltage. Europe is powered by 50 Hz and North America 60 Hz. Therefore, using the wrong format may make the image flicker under artificial lighting.
We recommend that you have your camera set to PAL TV mode and frequency to 50Hz.