A pixel having a reflector situated on a substrate. A temperature sensitive resistor may be situated over at least a portion of the reflector. An insulator may be situated on the resistor. The resistor and insulator may effectively be very thin films. A flat metal mesh or grid may be situated on the insulator. The grid, insulator and resistor may be supported by two or more posts at approximately one-fourth of a wavelength from the reflector. The wavelength may be that of the radiation to be sensed by the pixel. The thermal mass of the combination of the temperature sensitive resistor, insulator and grid may be less than several times the thermal mass of the grid. Since the grid may be so thin for low noise performance and high sensitivity, the grid can have a flatness assured to a desired extent with stiffeners attached to portions of it.