An unintended, but interesting effect. It was late afternoon, probably close to sunset but hard to tell since it was overcast, and had just started to rain. I saw this spindly tree with a tuft of flowers at the top and tried to take a picture, but it was too dim. So I stepped back, turned on the flash, and zoomed in. It made the flowers a lot brighter, and the sky a lot darker, than they looked in person.
You can actually see some of the raindrops caught in the flash.