Because the images are seldom used at real life size, any distance measured on the image must be multiplied by a constant conversion factor to expand it to its real life value. The standard procedure for determining the conversion factor is to place a meter stick in the camera's field of view during the filming. The CF is used to convert distances measured in millimeters on the projected image to real life distance in meters. It is often necessary to be able to determine time between special events when analyzing high speed film or video. Measuring the time can be accomplished by knowing the number of frames of film between two points of interest and the time per frame.
Video recording is less adjustable.
The time for one frame of film or video can be calculated from the camera speed setting. Sixteen frames from the jump have been saved as individual images for analysis. These were recorded at 15 frames per second and thus have time intervals of 0.067 seconds between pictures. The images that you will be analyzing are smaller than real life size and are scaled at 110 pixels per real life meter . Measure and record the horizontal and vertical position of the jumper's hip marker in each illustrated frame.