A novel stereo viewer designed for Salvador Dali

David ShaferDavid Shafer Optical DesignFairfield, CT. 06824#203-259-1431shaferlens@sbcglobal.net

Dali was once called “a genius, up to his elbow” because of his amazing technical skills, but crazy ideas – like his 1936 lobster telephone.

Dali’s mind-bending imagination, as shown in this elephants-on-stilts caravan painting,made him naturally interested in producing novel visual effects, such as double-image illusions and stereo.

The Spanish Surrealist artist Salvador Dali (1904-1989) had always been very interested in visual illusions. These aretypical ones of his.

In addition to “double images” like this one here, by the late 1970’s Dali had mastered the art of making stereo paintings pairs. He painted a right and left eye view of a scene like this one below.

6

Salvador Dali stereo painting pair, with about 8 distinct 3-D depth planes

Dali wanted a new type of stereo viewer to go with his innovative work. A limited edition of 2,000 stereo lithograph pairs were to be made from one of these works. His requirements for the viewer were:

1) highest possible optical quality2) lowest possible cost – use stock optics3) small size and weight4) adjustable for different viewing distances5) an aesthetically pleasing design

Dali wanted to decorate the viewer with some of his art. Ideally, we would open a small box and take out the stereo viewer, which would look like Dali’s face, and then look through his pictured eyes, on the viewer, at the stereo paintings.

When I met him Dali was an older man and not in the best shape, but his mind was tack sharp

9

In 1980 I met Dali for one hour and we discussed some ideas I had about how this might be done.

Later I had an important insight– there are twoequally legitimate ways to view the stereo pairs.

Obvious configuration

Less obvious solution

10

You just have to remember to switch the positions of the stereo paintings if you go for the alternate viewing configuration. If you don’t you get reverse stereo, which is hard on the brain.

The Wheatstone stereo viewer, from the late 1800s, is four flat mirrors and can be made to have several different solutions – where the lines of sight cross, or not, and where the rays are turned inwards or outwards with respect to the head. But there are unwanted lines of sight problems and to make it adjustable is more mechanically complex than is desired. Also, it is not new.

Deviating prism

wedges can make a

stereo viewer but they

have a lot of

dispersive color and

mapping distortion

and are not adjustable

for different viewing

distances.

I realized that a different ray path through a

prism can have no color, no distortion, and be

adjustable. There are two solutions, shown here.

The final viewer was just

two 45-90-45 degree

prisms with a flexible

hinge that joined them

along one prism edge.

They could be folded up,

when not being used, into

a larger size triangle.

I did not have to go

anywhere near a computer

to do this design project!

New type of stereo viewer

Arrangement when not in use and folded up

Works both ways, but having crossed lines of sight gives more room for eyes and nose and larger field of view.

Crossed lines of sight

This ray path, because of the reflection, does not give the usual color or distortion of prisms. It is equivalent to lookimg through a tilted thick parallel plate.

Prism pair is stored in box, with Dali face picture inside. His eyes, with holes for the pupils, are on the prism faces. You take out the prims viewer, unfold it with the adjustable hinge pivot, and look through Dali’s eyes through the prisms towards the stereo painting pair.

The hinge join is stiff so you can adjust the prisms for different viewing distances to the paintings and then it will stay that way by holding the viewer lightly in your hands.

It turns out that the non-obvious crossed lines of sight gives a bigger view of view through the prisms.

The right angle glass prisms were war surplus from Jaegers Optics on Long Island and had 50 mm X 50 mm faces. 2,000 sets of the prism viewer and a stereo pair of lithographs were sold for $5,000 a set. All were sold and the project took in $10,000,000 with minimal expenses. I got a very very tiny piece of that.

Towards the end of the project, back in 1981, I got a frantic call from someone preparing the sets to be shipped off. She complained of instant headaches when viewing the stereo lithographs. I asked her to put down the phone and switch the order of the lithographs and look at them. She came back in a few moments very relieved. Reverse stereo feels like your brain is being sucked out through your eyeballs. Not good.