Skip to main content

Sun Painting

Sun Painting
Sunlight–reflected and refracted–paints an ever-changing color composition.

Created by artist Bob Miller, this classic Exploratorium exhibit is a “live” painting that uses light from the Sun as its palette.

Sun Painting exhibit
Sun Painting exhibit
Sun Painting exhibit
Sun Painting exhibit
What’s going on?

On the roof of the museum, a device called a heliostat tracks the Sun throughout the day and reflects the Sun’s light through a window in the roof. Mirrors direct the sunlight through two banks of prisms, breaking it up into a rainbow of spectral colors. These dispersed colors are then recombined (thanks to more mirrors) on a giant screen “canvas” as a delicate, complex, and ever-changing pattern of color.

This extraordinary painting in light is a perpetual work in progress, responding to changing light conditions and to the presence of viewers, who, with their bodies, can block and sculpt the light that reaches the screen. (click image to enlarge)

Going further

Poet Muriel Rukeyser was so taken with this exhibit that she was inspired to write a poem about it, which she dedicated to the artist, Bob Miller. An excerpt from her poem accompanies the exhibit; the complete text appears below.

The Sun Artist
for Bob Miller


The opening of the doors. Dark.
The opening of the large doors.
Out of the daylight and the scent of trees
and that lake where generations of swans
no longer move among children. In a poisoned time.
But the bright-headed children move.

Dark, high, the beams of a huge building          

exposed in the high dark air.  

I see brightness with a shock of joy.


Past the darkness a lashing of color.
Not color, strands of light.
Not light but pure deep color beyond color,
like the pure fierce light I once knew, before

a minute of blindness. These colors are deeper;

the entire range in its millions,

twisting and brilliant traveling.


I stand in the strong sun before a bank of prisms.
On the screen in front of me, tangled colors of light,
                                                    twined, intertwined.
A sensitive web of light changing, for the sun moved, the

    air moves

The perceiver moves.

                                                    I dance my slow dance.


The deepest blue, green, not the streams of the sea,
the clear yellow of yellows, not California, more,
not Mediterranean, not the Judean steeps. Red beyond
                                                    blood over flame,
more even than visionary America.  All light,
A man braced on the sun, where the sun enters
through the roof, where the sun-follower,

A man-made motor with a gentle motion         

just counters the movement of the earth, holds this scene

in front of us on the man-made screen.

Light traveling, meets, leaps and becomes art.


Colors move on a screen. The doors open again.
They run in, the California children.
They run past the colors and the colors change.
The laughter of running. They cry out, bird-voices,
ninety seven children,Wow! Wow! Howcome?


Another day. I stand before the screen,

Alone I move, selecting out my green,
choose out the red with my arm, I let the orange stand,
a web of yellow, the blue stays and shines.
I am part of the color, I am part of the sun.


You have made an art in which the sun is standing.
It changes, goes dark, goes grey. The sun appears.
You have led me through eleven states of being.
You have invited us all. Allow the sunlight,
dance your dance.


Another day. No sun. the fog is down,
doing its slow dance into the city,
it enters the Gate and my waking.
There will be no colors but the range of white.
Before the screen, I wait.