Zootrope or Cinema's beginning Claire, Florence & Marina 2006

‘’Short stories’’ on technological progress in cinema:

1°/ As the saying goes, the horse is man’s best conquest…However, it is only around 1860 that gallop mechanism was understood thanks to Joseph Plateau and Etienne-Jules Marey and their theory on retinal persistency. Since legs movements of the galloping horse was too fast to be seen by any human eye,  Etienne-Jules Marey hit upon the idea of taking photos of a galloping horse using 10 photo cameras which worked every half second. Eventually, he discovered that every four seconds the horse doesn’t touch the ground for one second.

2°/ The first film was called ‘’Exiting the factory’’ and was made by the Lumiere brothers. It was about a few minutes long. Their very first film did not really tell something, it simply showed events of everyday life of an astounding banality. Yet since this exit from a factory no longer took place in real life but on a screen, it took a new dimension and its very nature changed. Thus, it could legitimately be said that this film, for the first time in history, ‘’narrated’’ the story of workers leaving the factory for lunch break.

3°/ The birth of cinema as an entertainment for masses dated back to December 28th 1895 on the day of the first public projection with admittance fee. It took place in the basement of the Grand Café restaurant in Paris. There, ten films which called by the Lumiere brothers ‘’vues’’ (pictures of everyday life) were shown.

4°/ ‘’The arrival of the train in La Ciotat train station’’ was a Lumiere brothers film shot in 1895. As a tradition, the picture of a train, which was straight coming, should terrified the audience who would shout and run at the back of the room. Hellmuth Karasek, a journalist, wrote in Der Spiegel : " This short film had long term consequences. Yes, it provoked fear, terror and even panic…". This story was told many times in numerous publications but also thanks to word of mouth.

One of the key-concept: retinal persistency

        Have you ever observed a roll of cinema film? It is composed of series of images which are projected at a speed of 24 images a second with an obturator shutting in-between each exposure. Why do we see a continuous movement rather than the flashing of the images? This is due to a phenomenon directly linked to human eye operation called retinal persistency. When the crystalline lens projects an image on the retina, the transformation of the photoreceptor cells pigments (cones and rods) is translated into an action potential which is transmitted to the brain. When the image is interrupted, the chemical activity remains within the photoreceptor cells and keeps nerve impulse for a short time (a few hundredth second). Therefore, it gives people the feeling of a continuous movement. Thus, when images appear at a quite high speed, one’s eye keeps the previous picture in mind until the following one appears. It is as if the eye would ‘’forget’’ black screens. This time limit between two images can be increased if the intensity of the surrounding light decreases. This is why it is very dark in movie theatres! Moreover, old black and white movies seem to be shown in a speeded-up motion, it is because they were shot with a 16 images a second speed instead of 24 which is nowadays standard, retinal persistency being approximately 40ms.

It’s your turn now to make a zoetrope!

Step 1: Prepare the required equipments

• 1 cylindrical pen
• 1 cylindrical lid (internal diameter : 10 cm)
• 1 cardboard strip (33cm*6cm) black on one side and white on the other.
• 1 scissor
• 1 saw
• 1 graduated ruler
• some glue

Step 2: The making of the zoetrope

Dismantle the ball-point pen in order to have the body on one side and the ink tank and the point on the other. Saw the body 8 cm above the lower part Put the hollow part of the lid facing up. Then, with the scissors point pierce a hole in the centre Put the ink tank into this hole. Set up the pen body around the ink tank.

On the cardboard strip, draw 10 rectangles (3cm / 0.5cm) with regular intervals as it is shown on the following picture and then cut those rectangles.

Reproduce or copy the following picture enlarging it in order to get a 33cm/ 3cm paper strip.

Every 3,15cm, the drawings show spectators doing a "ola".

Set up the card board strip inside the lid, its crenels facing up and its white side inside.

Stick the overlapping edges of the strip to obtain a cylinder.

Set up the paper strip inside the cardboard cylinder. Make sure the drawings are on view.

Stick the overlapping edges of the paper strip.