[...] an image from a book on early color pho­tog­ra­phy, where the ama­teur pho­tog­ra­pher was encour­aged to some­how mem­o­rize the dif­fer­ent col­ors of day­light in rela­tion to the height of the sun in degrees… imag­ine hav­ing to cal­cu­late that before being able to chose the right fil­ter and take your snap­shots! Today’s pro­sumers just set the white bal­ance of their dig­i­tal cam­era, and don’t pay much atten­tion to what the color of the light might be at any given moment, or what that might add to their image — as long as those tiles stay per­fectly white.