Analyte arrays such as solutes in a slab-shaped gel following electrophoresis, and particularly arrays that are in excess of 3 cm square and up to 25 cm square and higher, are imaged at distances of 5 cm or less by either forming sub-images of the entire array and stitching together the sub-images by computer-based stitching technology, or by using an array of thin-film photoresponsive elements that is coextensive with the analyte array to form a single image of the array.