A Multiview Stereoscope Comparison

written for the stereosite by André Ruiter, The Netherlands

I have been col­lect­ing stere­oscopy antiques for some years now. My most cher­ished pieces in my col­lec­tion are the mul­ti­view stere­o­scopes. I thought it would be inter­est­ing to com­pare these stere­o­scopes based on their mech­a­nism which is used to posi­tion the stereo views in front of the lenses.

Mul­ti­view stere­o­scopes are table stere­o­scopes that are capa­ble of show­ing mul­ti­ple images in one view­ing ses­sion. These view­ers use a slide tray or chain in which the stere­oviews are placed. By turn­ing a crank or push­ing down a lever, the images are dis­played one by one. The mul­ti­view­ers with slide trays are only suit­able for glass stere­oviews. The chain view­ers are also avail­able for paper stere­o­cards and some­times they sup­port both glass and paper stereoviews.

To com­pare the mul­ti­view­ers, I use four cat­e­gories: Chain, Lift­ing, Pick-Up and Grav­i­ty. I came up with these cat­e­gories myself so they’re not com­mon­ly used clas­si­fi­ca­tions among enthusiasts.

Chain stereoscopes

The revolv­ing chain types are the old­est mul­ti­view stere­o­scopes. They were pro­duced from 1860 and are based on a patent of Alexan­der Beck­ers from New York. They are there­fore also called Amer­i­can or Beck­ers stereoscope. 

This type of mech­a­nism includes a chain and hold­ers. The chain is made of wood and iron or com­plete­ly iron for view­ers that sup­port heav­ier glass slides. A stere­oview is placed in each hold­er. By turn­ing a knob, the stere­oview is placed in a ver­ti­cal posi­tion in front of the lens­es. Turn­ing the chain fur­ther will dis­play the next stere­oview. A chain can usu­al­ly have 50 stere­oviews, but there are also tall floor stand­ing mod­els that are suit­able for 100 or 200 images. The view­ing expe­ri­ence isn’t great with these view­ers and replac­ing the stere­oviews can be cum­ber­some. Some mod­els allow remov­ing the entire chain with hold­ers from the device, which will make replac­ing the stere­oviews eas­i­er. Most Eng­lish and France man­u­fac­tur­ers from 1860 to 1930 had a revolv­ing chain type stere­o­scope in their prod­uct range.

Lifting stereoscopes

These are the most sophis­ti­cat­ed stere­o­scopes. They use a bake­lite or wood­en slide tray to place the glass slides. A slide tray has room for around 25 slides. Depend­ing on the mod­el, spe­cial trays for the thick­er Autochrome slides are also available.

The lift­ing stere­o­scopes use an advanced mech­a­nism, often with gears and springs to dis­play the stere­oviews. The tray with glass slides is placed in the device. By turn­ing a crank or press­ing down a lever, a stere­oview is pushed up from the tray by a met­al pin and is placed in front of the lens­es. Rotat­ing fur­ther low­ers the stere­oview and places it back in the tray. With­in the same move­ment, the tray is moved for­ward over a rail so the next slide can be lifted.

The lift­ing stere­o­scopes are user friend­ly and offer a good view­ing expe­ri­ence. They require that the mech­a­nism is in good work­ing con­di­tion because a slight mis­align­ment will cause jam­ming and can break your glass slides. Some exam­ples of lift­ing stere­o­scopes are the Tax­iphote of Jules Richard, Unis France Métas­cope, Gau­mont Stéréo­drome, Erne­mann Mag­a­zin and the table stere­o­scopes of Hemdé.

Pick-Up stereoscopes

This is a vari­a­tion on the lift­ing stere­o­scopes. It was an inven­tion of Alexan­der Plocq from Paris and his Planox Stéréo­scope Mag­né­tique are the only mod­els that work this way. The mech­a­nism works rough­ly the same as the lift­ing stere­o­scopes, but instead of lift­ing the slides they are picked up by a mag­net. Each slide has to be pro­vid­ed with a met­al strip at the top to make the slides magnetic.

The mech­a­nism works well in prac­tice, but I don’t see any real advan­tages com­pared to the lift­ing devices. A dis­ad­van­tage is that you have to pro­vide every slide with a met­al strip. Once attached, you should leave it because remov­ing them can dam­age the glass and the emulsion.

Gravity stereoscopes

This type of stere­o­scope excels because of its sim­ple mech­a­nism. It uses grav­i­ty to place the slides by a “falling motion”. The lack of a sophis­ti­cat­ed mech­a­nism allows a com­pact design. The first exam­ple is the Mul­ti­phote, designed by Lucien Bize.

The Mul­ti­phote tray with 24 slides is placed on the top sec­tion of the device. By remov­ing a met­al slide at the bot­tom of the tray, the slides fall into posi­tion. The emp­ty tray is now placed in the bot­tom part of the device to catch the slides.

By turn­ing the knobs, the view­er part with the lens­es moves out­ward and the rear­most slide falls down and is placed in view­ing posi­tion. By turn­ing the knobs a lit­tle bit fur­ther, the slide drops into the slot of the slide tray. This pro­ce­dure is repeat­ed for every slide. After view­ing all the slides, the tray can be removed from the bot­tom part to reload the device. 

The sec­ond exam­ple is the ICA Stere­ospekt from Ger­many. The slides of the Stere­ospekt are mount­ed in a met­al har­mon­i­ca belt with frames. The belt can con­tain up to 12 slides. The slides are firm­ly clamped in frames, which indi­cates that the slides should remain per­ma­nent­ly in the belt. By depress­ing a small lever on the right side, the slides are released and “fall” in front of the lenses.