This photo of him in a road game was a tough one, but I think I’ve got it figured out.
Getty Images, where the photo came from, says it’s from the “late 1950s.” That has to be 1957 or later, because the Cubs only started wearing that style of road uniform (with the piping on the sleeves and collar and pants) that year.
So your next clue is the catcher. Only one National League team wore uniforms like that in that era — the Phillies. So this photo, then, was taken at Connie Mack Stadium in Philadelphia. The Cubs wore road uniforms like that through 1968.
There’s a zero in the catcher’s uniform number. There were only two men who caught for the Phillies and wore a number ending with zero in that era — Jimmie Coker (1960-61) and Cal Neeman (also 1960-61, and a former Cub). Both wore No. 10.
Coker caught the 1960 game; Neeman, the 1961 game.
Both Banks and the catcher are wearing long sleeves, and the shadows look too long for it to be August, so I’m pretty sure this was taken April 23, 1961. The first game of that doubleheader (Neeman didn’t catch the second game) began at 1:05 p.m. local time and it ran 2:01, thus ending a little after 3 p.m. local time. Sunset in Philadelphia on April 23, 1961 was 6:46 p.m. Shadows are just starting to creep past the stands, so I’m going to say this photo was taken near the end of that first game, which went into the bottom of the ninth in a scoreless tie. Banks batted in the top of the ninth and singled, but was stranded. The photo could be of Ernie’s single. The Phillies won 1-0 on a walkoff home run by Bobby Smith off Dick Ellsworth.
Just another slice of baseball history, sleuthed out. Here’s a larger version of the photo at the top of this post.