The photo above doesn’t need any sleuthing, because the caption that came with it tells the date:
A large plastic screen, center, blue in color, makes its appearance in the bleachers as an experiment to eliminate the glare from white shirts in Wrigley Field, July 22, 1943, Chicago, Ill. This screen was placed in line with vision of right handed hitters, if successful it will be extended to include vision of left handers.
So, now we know when this photo was taken. The purpose of this post isn’t sleuthing, instead, it’s to note the “large plastic screen” that was placed in front of some people in the center-field bleachers to attempt to give hitters a better look at pitches.