The present disclosure relates to spatially modulating the light source used in microscopy. In some cases, a light source projects a sequence of two-dimensional spatial patterns onto a sample using a spatial light modulator. In some cases, the spatial patterns are based on Hadamard matrices. In some cases, an imaging device captures frames of image data in response to light emitted by the sample and orthogonal components of the image data are analyzed by cross-correlating the image data with the spatial pattern associated with each frame. A microscope may be calibrated by illuminating a sample with the sequence of spatial patterns, capturing image data, and storing calibration that maps each pixel of the spatial light modulator to at least one pixel of the imaging device.