2015-09-06 Links for calculating sun light PBR CG Brightness and Flux Density http://www.cv.nrao.edu/course/astr534/Brightness.html How do I calculate the apparent brightness of a mirror reflecting the sun at a given distance? http://physics.stackexchange.com/questions/153870/how-do-i-calculate-the-apparent-brightness-of-a-mirror-reflecting-the-sun-at-a-g 光と光の記録 - 光編 http://www.anfoworld.com/Lights.html#sun