This invention provides an imaging system for high-accuracy quantitative analysis of a microarray. In certain embodiments, the system comprises a broad band excitation light source that provides Kohler illumination of said microarray at an incident angle that ranges from about 30 degrees to about 75 degrees from the normal to the microarray, and that has less than about .+-.25 percent variation in intensity over the array at all wavelengths ranging from 400 to 800 nm; a support for holding a microarray; a detection lens system that is chromatically corrected so the apparent position of the microarray or a feature comprising the microarray varies by less than 10 .mu.m as the detection wavelength varies from about 400 to about 800 nm; and a detection device for detecting and optionally recording an image produced by said detection lens system.