The video camera is set so a sheet of 2 to 8 meters of paper with black marker lines every ten centimeters are viewed. By making the height less, you sacrifice fall time and the acceleration might not be as clear. Making the height greater would require a big room, tall ladder and a video camera with an extra-wide lens.
The ball is held at the top black line and released. The camera will record the ball's motion. The tape can be played through on a VCR using the FRAME ADVANCE option to page through the images. The distances can be measured on the black lines and the time is equal to the number of images scrolled through plus one with each image counting as 1/30th of a second