Optical filter opacity control for reducing temporal aliasing in motion picture capture

A system comprising:

• an image sensor configured to generate a plurality of consecutive image frames;
• an optical filter having an opacity that is adjustable, the optical filter being disposed in an optical path of the image sensor and configured to vary an amount of light incident on the image sensor responsive to a control signal;
• and
• a controller configured to generate the control signal to vary the opacity during individual image frame periods of the plurality of consecutive image frames so that:
• the opacity decreases during a first part of the individual image frame periods and increases during a second part of the individual image frame periods, and
• object motion above a Nyquist frequency is filtered by the optical filter prior to detection by the image sensor.

A method comprising:

• generating, with a processor, a control signal to control an opacity of an optical filter disposed in an optical path of an image sensor;
• varying the opacity during individual image frame periods of a plurality of consecutive image frames responsive to the control signal so that:
• an amount of light incident on the image sensor varies during the individual image frame periods,
• the opacity decreases during a first part of the individual image frame periods and increases during a second part of the individual image frame periods, and
• the opacity varies during the individual image frame periods in a way that diminishes an impact of temporal aliasing that is capturable by the image sensor;
• and
• generating, with the image sensor, the plurality of consecutive image frames responsive to the light incident on the image sensor.