52 Cameras: Camera 76 part 1 – FujiFilm Instax Mini 7S
Channel: 52 Cameras
Date: 2015-09-21

The chart showing varying shutter:
https://en.wikipedia.org/wiki/Instax#Instax_Mini_Cameras

The review giving varying f-stops:
http://120studio.com/review-instax-mini.htm

Results and hopefully a definitive answer to the exposure settings question will be at:

 http://exit272.com/?p=2337