[En] Review: ⌀20cm Praxinoscope by Hemisferium

I got the opportunity to play with early cinema technology targeted for the victorian age markets. The contraption is called a Praxinoscope. Our device was bought online. It’s made to look as it’s old in hopes of appealing to vintage-fans. But the frame is plastic. The device was build in Spain by a company called Hemisferium.

Outi Heiskanen has contracted me to assist in the construction of “primitive moving image technologies”. We bought this device as we couldn’t find any decent tutorials on how to build one ourselves. It’ll be pimped (or we’ll build a new device based on the model) if this technology will be used in her art exhibitions etc. A couple of years back we started working on “Tibetan Candle Turbine” technologies and since this I’ve experimented with a variety of low-tech image projection techniques. A highlight of which was the discovery of parabolic mirror projections (which Paula L. now owns).

For the praxinoscope tests we compressed the “Starswing” animation we made with Outi into 12 frames. The outer rim of the Hemisferium praxinoscope is ⌀20cm so the animation stripes which it uses need to be ~61cm long. This is nice as a 12 frame animation may be fitted on a A4 paper. A A4 print can compress 1sek of animation!! If the prints are made in 300dpi then it could be called a HD moving image screen. The bit rate is high. The printed strips need to be cut from the sheet and glued together.

The quality of the Hemisferium praxinoscope mirrors is shitty. They are made from plastic which add to bad luminosity. The “mirrors” are bend and distort the images too. They are tinted brown to add vintage appeal which is annoying. The device came pre-assembled and there are a lot of problems.. The axis is tilted.. The frame is wiggly. It’s a shitty piece of equipment but it works for testing. There are no labels on the device and it cannot be disassembled without braking the frame. So I made a simple 3d model of the device which can be used to check the measurements incase you want to build one your self. Here are some measurements:

Diameter of outer-rim 205mm. Inner-rim ~100mm.
12 x Mirrors ~28mmX70mm.
The animation sheet is 610mm long and 45mm high.
12 images have 50mm of distance from each other.
Now that we have tested the system we’ll make better prints of the animation (ink was low) and possibly build a more advanced praxinoscope with real mirros etc. Let’s make GIF animations tangible!