Previous studies have painted a conflicting picture on the amount of visual information humans can extract from viewing a natural scene briefly. Although some studies suggest that a single glimpse is sufficient to put about five visual objects in memory, others find that not much is retained in visual memory even after prolonged viewing. Here we tested subjects' visual working memory (VWM) for a briefly viewed scene image. A sample scene was presented for 250 ms and masked, followed 1000 ms later by a comparison display. We found that subjects remembered fewer than one sample object. Increasing the viewing duration to about 15 s significantly enhanced performance, with approximately five visual objects remembered. We suggest that adequate encoding of a scene into VWM requires a long duration, and that visual details can accumulate in memory provided that the viewing duration is sufficiently long.