The Tunnel of Paintings

1. The Tunnel and the Sequence

Imagine looking through a long tunnel extending toward infinity.

The tunnel is not empty. It contains grass, flowers, trees, houses, roads, clouds, and distant hills. Every object occupies a position within the tunnel. Some are near. Some are far away. Some extend through large parts of the tunnel.

Now imagine that the tunnel contains a sequence of paintings.

Each painting corresponds to a particular distance.

The paintings are arranged in perfect order. The first painting represents the nearest visible distance. The last painting disappears somewhere near infinity. Between them lies an enormous sequence of paintings, each corresponding to a slightly different depth within the world.

A tree does not belong to a single painting.

The front leaves may appear in one painting. The trunk may appear in another. The rear branches may appear in yet another. The tree occupies many neighbouring paintings because the tree itself has depth.

A house occupies several paintings. A road occupies hundreds. A mountain may occupy thousands.

The world is not flat.

The world extends through the sequence.

2. Focus Selects One Painting

When we focus a lens, something interesting happens.

The tunnel itself does not move.

The paintings do not move.

The tree does not move.

Instead, the lens selects one painting to be shown most clearly.

As the focus ring is turned, the selected painting moves forward or backward through the sequence. One distance becomes clear, then another, then another.

The selected painting is never completely alone.

Neighbouring paintings remain faintly visible.

3. Neighbouring Paintings

They appear as softness, blur, hints of structure, gentle shadows, and partially formed detail. They are no longer the main painting, but they have not completely disappeared.

Sometimes these neighbouring paintings reveal themselves in unexpected ways.

A photographer focusing on a tree may notice faint red, green, or magenta details along branches and twigs. These details may appear to shimmer slightly before disappearing again when focus is adjusted.

It is tempting to assume that the lens is creating these colours. Sometimes it may be. But often the explanation may be simpler.

4. The Tree and the Coloured Echoes

The branches belong to neighbouring paintings.

The tree is not a flat object. Some branches are slightly nearer. Others are slightly farther away. When focus is set on one part of the tree, the remaining parts still contribute to the image, but not with full clarity. They arrive as echoes from nearby paintings.

As focus moves, the echoes move too.

A branch that was previously only hinted at may suddenly become crisp and fully formed. Another branch may now retreat into softness and colour.

The architecture has not changed.

Only the selected painting has changed.

Stopping the lens down often makes this effect less obvious. More neighbouring paintings are allowed to contribute in an orderly manner. The coloured echoes become weaker and more of the tree appears coherent at the same time.

These neighbouring paintings are important.

Without them, the image would become strangely flat.

5. How Depth Emerges

The traces from nearby paintings tell us that the tree has volume. They tell us that the road continues away from us. They tell us that the house stands behind the tree rather than beside it.

Depth is not drawn directly.

Depth emerges from the relationship between the selected painting and its neighbours.

The photograph therefore contains more than a single distance.

It contains echoes of nearby distances.

Perhaps this is one way to think about what a lens really does.

The lens looks into a tunnel filled with architecture. Every visible point contributes its own light and colour. The lens selects one distance to show most clearly while allowing traces of neighbouring distances to remain.

From these traces, a flat image acquires depth.

And from that depth, the observer reconstructs a three-dimensional world.