The photograph is 105 x 60mm with a large mount measuring 205 x 150 mm, the full extent of which is not shown in the image. Jane says, "I found this photo in an old box. My gg-grandfather Walter Baker (born 1859, Heckworthy, Devonshire & died 1950, Derby, Derbyshire) is seated in the front row, third in from the right, with his black hat on his knee." However, she knows nothing more about it.
I estimated that it was possibly taken between 1910 and 1920, and that it could have been a church outing, but I don't have any more bright ideas at the moment. If any reader thinks they can tell us more, please Email me.
P.S. Nigel Aspdin suggests that the building just visible in the background might be a "tin tabernacle."