A solar simulator for testing solar cells comprising: an array of lamp modules configured to be imaged on a target plane on surfaces of the solar cells, wherein each lamp module of said array comprises: a lamp configured to generate light; a homogenizer having an input end and an output end; a beam divergence lens positioned to focus said light onto said input end of said homogenizer; and an imaging lens positioned to receive said light from said output end of said homogenizer and image said light onto the target plane, wherein each lamp module of said array further comprises a spectral filter, wherein said spectral filter of at least one lamp module (14A, 14M) of said array is configured to provide substantially full spectrum illumination, and wherein said spectral filter of at least another lamp module (14B-14G, 14N-14S) of said array is configured to provide a specific non-full spectrum band of illumination, wherein the solar simulator is configured to control said intensity of said light from each lamp module of said array, wherein each lamp is electrically coupled to a power supply, wherein the solar simulator comprises respective variable voltage/current devices for each lamp configured to control the power supplied to the lamp, wherein the solar simulator comprises a controller configured to control each variable voltage/current device such that power supplied to each lamp of respective lamp modules is controlled independently of other lamp modules, wherein the controller is configured to control the intensity of the full spectrum lamp modules (14A, 14M) to adjust up or down a baseline spectrum of illumination on the target plane, wherein the controller is configured to control the intensity of the at least another lamp module (14B-14G, 14N-14S) to modify the spectral distribution of the illumination on the target plane. an array of lamp modules configured to be imaged on a target plane on surfaces of the solar cells, wherein each lamp module of said array comprises: a lamp configured to generate light; a homogenizer having an input end and an output end; a beam divergence lens positioned to focus said light onto said input end of said homogenizer; and an imaging lens positioned to receive said light from said output end of said homogenizer and image said light onto the target plane, a lamp configured to generate light; a homogenizer having an input end and an output end; a beam divergence lens positioned to focus said light onto said input end of said homogenizer; and an imaging lens positioned to receive said light from said output end of said homogenizer and image said light onto the target plane, wherein each lamp module of said array further comprises a spectral filter, wherein said spectral filter of at least one lamp module (14A, 14M) of said array is configured to provide substantially full spectrum illumination, and wherein said spectral filter of at least another lamp module (14B-14G, 14N-14S) of said array is configured to provide a specific non-full spectrum band of illumination, wherein the solar simulator is configured to control said intensity of said light from each lamp module of said array, wherein each lamp is electrically coupled to a power supply, wherein the solar simulator comprises respective variable voltage/current devices for each lamp configured to control the power supplied to the lamp, wherein the solar simulator comprises a controller configured to control each variable voltage/current device such that power supplied to each lamp of respective lamp modules is controlled independently of other lamp modules, wherein the controller is configured to control the intensity of the full spectrum lamp modules (14A, 14M) to adjust up or down a baseline spectrum of illumination on the target plane, wherein the controller is configured to control the intensity of the at least another lamp module (14B-14G, 14N-14S) to modify the spectral distribution of the illumination on the target plane.