def calcCropSensorWidth(sensorWidth, nativeAspectRatio, mediaAspectRatio):
    """
    Calculate effective/utilised width of camera sensor when image/video is
    recorded at non-native aspect ratio.
    """

    cropRatio = (nativeAspectRatio[1] / nativeAspectRatio[0]
                 ) / (mediaAspectRatio[1] / mediaAspectRatio[0])
    return sensorWidth * cropRatio