1. A method for synthesizing an image from multiple images captured from different viewpoints using an array camera in low light conditions, the method comprising: capturing image data using a plurality of active cameras within an array camera, where the plurality of active cameras are configured to capture image data within the same spectral band and the image data captured by the active cameras comprises pixel brightness values that form a reference image and a plurality of alternate view images captured from different viewpoints; applying geometric shifts to shift the plurality of alternate view images to the viewpoint of the reference image using the processor configured by software; summing the pixel brightness values for pixels in the reference image with pixel brightness values for corresponding pixels in the alternate view images to create pixel brightness sums for the pixel locations in the reference image using the processor configured by software; and synthesizing an output image from the viewpoint of the reference image using image data comprising the pixel brightness sums for the pixel locations in the reference image using the processor configured by software.