Humans are experts at remembering and recognizing faces. It is now well established that we have photographic memories of familiar faces such as relatives, and public figures. It is however unclear s to the quality of our memory of unfamiliar faces we are exposed to for a short period of time. In the present study, 34 participants studied a target faces only once for 10, 20, or 30 seconds. Afterwards, they were asked to respond SAME or DIFFERENT when seeing either the same target face or a different foil face. The target face differed from the foil faces on a single dimension of difference: the distance between the eyes, which was changed by varying the distance in pixels between the eyes of the target face. Foil faces changed from a very large 10 pixel distance greater than the target's inter-ocular distance to 10 pixels less than the target's inter-ocular distance. There were 500 target face trials and 500 foil face trials. Participants received no feedback. Response choice and response time were measured. There was no feedback. Results showed that in the 20 and 30 second study conditions the participants performed above chance from the outset ( 74% and 80% respectively), and though receiving no feedback, still improved their identification of the target faces across trials. Performance seems to stabilize from trials 600 to 1000. The 10 second study condition shows a diminution in performance nearly reaching a level of chance performance. The same experiment was run with a new face. These findings were replicated. Based on the SAME response data, we estimated that to obtain a high level memory performance of an unfamiliar face (>.75), the minimal exposure time appears to be between 20 and 30 seconds.