lighttestdaybad02
(This photo is part of a series, testing out the manual film-speed settings of my new Nikon Coolpix S550. See the first photo of this set for a VERY long explanation of how this test was conducted.)
But then here you see the problem with forcing a high-speed film in a low-speed situation; that since such film needs such profoundly less light, it tends to get severely overexposed in bright situations like the sky. That's why one generally uses slower speeds in daytime situations, because the grain of the film is more suited for bright surroundings, and thus you're given more leeway for capturing a richer range of grays.