Interesting conversation on MacBreak Weekly about how low light impacts on video quality when using Google Hangouts or Skype. With low light, you need more gain, which means a more grainy video. More grainy video interestingly requires more bandwidth, so as a result services such as Google Hangouts or Skype have problems and downgrade the quality or buffer the video.
So if you use Google Hangouts, you may be at home or in the office, you very likely don’t have any studio lights (why would you) and therefore the environment is probably darker.
So if you are having connection issues using a Google Hangout, laggy video, latency issues, buffering, you might want to turn the lights on.