Some embodiments relate to an imaging apparatus. The imaging apparatus includes a light source that emits coherent light to image an object. The imaging apparatus also includes an optical apparatus that optically processes light from the object. The optical apparatus has a numerical aperture. The imaging apparatus also includes an imager that receives the light optically processed by the optical apparatus. The imaging apparatus also includes circuitry configured to obtain speckle data based on the light received by the imager and control the numerical aperture of the optical apparatus based on the speckle data.
