An apparatus for controlling the quantity of light incident on an image sensor by controlling size or shape of a diaphragm and also by adjusting light transmittance of the diaphragm is provided. The light control apparatus is disposed on the light path of the image sensing device and controls a quantity of light incident on the image sensor. The light control apparatus includes a Guest-Host LCD panel applied no polarizing film and a control unit for reducing the time to take multi-frame detection by driving voltages which are applied to respective pixels of the Guest-Host LCD panel, to be increased at least when taking multiple frames in series. The Guest-Host LCD panel has a plurality of pixels forming closed curves or boundaries on a plane, which are electrically driven individually. Also, the pixels have uniform light transmittance throughout the entire azimuth of the closed curves or boundaries with an origin.