An optical sensor includes an array of pixels configured to convert photons into electrons for forming an image. A tunable filter assembly is optically connected to the array of pixels for passing an adjustable bandwidth of photons to the array of pixels. The tunable filter assembly includes a first mirror defining an optical axis and a second mirror spaced apart from the first mirror along the optical axis. A first electrode is mechanically connected to the first mirror and a second electrode is fixed relative to the second mirror. The first and second electrodes are positioned relative to one another to adjust the position of the first mirror with respect to the second mirror when a voltage is applied across the first and second electrodes to tune the spectral bands being passed through the filter assembly to the array of pixels.