1. A system, comprising: a sensing system that produces a digital image of a viewing area of a sample holder, the sample holder holding a set of cells; a motion system that changes the relative positions of the sample holder and the sensing system to a plurality of configurations, such that the viewing area encompasses a different viewable portion of the sample holder in each configuration, wherein the encompassed viewable portions are arranged generally transversely with respect to a primary loading direction of the sample into the sample holder; and a controller that directs the sensing system to capture a digital image when the sample holder and sensing system are in each of the plurality of configurations.