Interpolation between the same point in space (pixel) on successive frames. It can be used to provide motion smoothing and is extensively used in standards converters to reduce the judder caused by changes of field, or frame, rates such as between 50 and 60 Hz. The technique can also be adapted to create frame averaging for special effects and slow motion. Various qualities of processing are used. It can be very complex, attempting to work out how each element in successive pictures is moving in order to synthesize ‘between’ images (e.g. to convert 50 pictures into 60 pictures while still showing smooth motion).