An optical filter assembly having selectable bandwidth is presented. The optical filter assembly includes a first optical filter, a first optical retarder with optical retardance R1, a second optical retarder with optical retardance R2, a polarization switch positioned between the first and second retarders which causes their retardances to substantially add in a first switch setting and to substantially subtract in a second switch setting, and an exit polarizer. A multispectral imaging system using tunable optical filters having selectable bandwidth is presented. A method of filtering light is also presented. The method includes providing a first optical filter, providing a dynamic bandwidth stage including a polarization switch, selecting a first setting of the polarization switch, and producing a first filter action for light passing through the first filter and the dynamic bandwidth stage.