1. A method for synthesizing an image from multiple images captured using an array camera in low light conditions, the method comprising: capturing image data using at least one active camera within an array camera, where the image data captured by the at least one active camera comprises pixel brightness values that form a reference image and a plurality of alternate images captured at different times; applying geometric shifts to shift the plurality of alternate view images to the viewpoint of the reference image using a processor configured by software for alternate images that are not from the same viewpoint of the reference image; summing the pixel brightness values for pixels in the reference image with pixel brightness values for corresponding pixels in the alternate 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.