The first photograph of a person took ten minutes to expose.
Why it is true
In the famous image of the Boulevard du Temple in Paris, the street looks empty because the traffic didn't stay still long enough. Only a man getting his shoes shined stayed still long enough to be captured.
Source: Getty Museum
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.