PINHOLE CAMERA / CAMERA OBSCURA

What Is a Pinhole Camera?

Q: Can I make a pinhole camera myself?

Yes. A pinhole camera can work with a light-tight box, a pinhole and a light-sensitive surface. Aperture precision and excluding stray light are essential.

A pinhole camera forms an image using light passing through a small hole instead of a lens.

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Pinhole camera: a 3D explanation

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A 3D view follows light reflected from points on a tree through a small hole to an inverted image. It compares how small and large openings change each point’s footprint and the clarity of the image.

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Sunlight reaches the tree and reflects from each point on its surface in many directions. Different colors distinguish light from the top, middle and bottom of the tree. The rays spread in depth as well as across the screen.

A dark box with a small opening stands between the tree and the screen. Light that strikes the wall stops there; only the portion directed toward the opening enters. Light from different points passes through at the same time. The opening neither bends nor converges the rays.

Light continues straight after passing through the opening. Light from the top of the tree reaches the bottom of the screen, light from the bottom reaches the top, and light from the middle reaches the middle. The resulting tree image is inverted vertically and horizontally.

The viewpoint travels along the light path: from the sun to the tree, from reflection at the tree toward the opening, and through the opening to the screen inside the box. Outside and inside views show that the path remains straight.

With a small opening, light arriving from one point on the tree makes a small circular footprint on the screen. More footprints, corresponding to different points, gradually appear and combine to form the fine outline of an inverted tree.

The opening grows while the tree and screen stay in place. The footprint from the same point becomes larger. Large footprints from many points overlap and blur the outline. The final side-by-side comparison connects the size of each footprint with the appearance of the whole image.

The rays and opening are enlarged schematic representations, and the circles explain how the image forms. Brightness is adjusted for the comparison. A smaller opening does not make the image indefinitely sharper: diffraction also causes blur when the opening is too small.

A pinhole camera is one of the simplest photographic devices. Instead of a lens, it forms an image from light entering through a tiny aperture. Because it relies directly on light traveling in straight lines, the image emerges through specific conditions: aperture size, distance and time. This page considers pinhole photography and the relationship between the pinhole camera and camera obscura through principle, structure, history and expressive possibilities.

01 / PRINCIPLE

How a Pinhole Camera Works

A pinhole image is created as light travels in straight lines through the aperture and is projected onto a surface. A larger aperture admits more light but produces a softer image. Reducing the aperture tightens the image within a certain range, but requires a longer exposure; if it becomes too small, diffraction softens the image again. This trade-off between brightness, sharpness and time is fundamental to the pinhole camera.

Aperture diameter: Affects image sharpness and brightness
Projection distance: Affects image size and brightness
Exposure time: Determines whether the image can be formed

30 SEC / COMPARISON

See the Difference in 30 Seconds

Both systems form an image, but light travels through them in fundamentally different ways.

01 / PINHOLE

A pinhole does not bend light

Object → small opening → screen

Each ray continues along the same straight line before and after the opening. The hole forms an image by limiting which directions can pass, not by gathering light.

Try the pinhole model

02 / LENS

A lens bends and gathers light

Object → refracting lens → image plane

The lens refracts spreading light so it converges at an image point. If the image plane misses that point, the bundle still has width and appears blurred.

See how a lens works

03 / COMMON

Both systems invert the image

Light from the object’s top reaches the image bottom, and light from the bottom reaches the top. The difference is straight travel through a hole versus refraction and convergence through a lens.

Fading Light, an artwork with blue light and a white circular image in darkness — Fading Light / 2021

02 / DEFINITION

Definition of a Pinhole Camera

A pinhole camera forms an image with light passing through a small aperture instead of a lens. Unlike conventional cameras optimized for sharpness, a pinhole camera makes the conditions of image formation—exposure time, aperture diameter and subject distance—especially visible.

It can therefore be treated both as photographic equipment and as an apparatus for observing the behavior of light and the assumptions behind vision.

03 / STRUCTURE

Minimum Structure

A pinhole camera has three essential elements.

01A light-tight box: a space that controls light
02A pinhole: the entrance for light
03A light-sensitive surface: film, photographic paper or an image sensor

This structure can be enlarged easily. A larger box becomes a giant camera; if a building or room is made light-tight and an aperture is opened, the space functions as a camera obscura.

A photographic apparatus built from cardboard — Cardboard Digital Camera No. 3 for heuristic, 2011

04 / CAMERA OBSCURA

Relationship to Camera Obscura

A camera obscura projects the scene outside onto a surface inside a darkened room or box. It can use a small hole or a lens.

A pinhole camera forms an image through a small hole instead of a lens. It shares its principle with a lensless camera obscura, but either can take the form of a box or a room, so size or portability alone does not distinguish them.

The apparatus used to make Corridor of Time — Camera for Corridor of Time, 2006

05 / HISTORY

A History of the Pinhole Camera

The observation that an aperture forms an image was recorded more than two thousand years before photography. The essentials are below. The full fourteen-stage chronology, eight side stories and twenty-four sources are gathered on a separate page.

c. 4th–3rd century BCE
The MoziLight crosses at a small aperture; the image is inverted
Early 11th century
Ibn al-HaythamDescribes image formation through a small aperture in a dark space
1544
Gemma Frisius observes an eclipsePublishes the projection into a darkened room as an illustration
c. 1826–1827
NiépceKeeps a projected image permanently — photography begins
1890
George DavisonPinhole photography is recognised as expression

06 / EXPRESSION

Pinhole Photography as Expression

Pinhole photography is more than simply “retro” or “soft.” By stepping away from the lens-based values of resolution and focus, it can make the conditions through which an image appears into the subject of the work itself.

The image appears as a set of conditions: time, distance and aperture
The idea of a single focus weakens and the space becomes more even
Designing the apparatus becomes part of the act of making

07 / FAQ

Frequently Asked Questions

How does a pinhole camera work?

Light travels in straight lines through a small hole and projects an inverted image on the inside of a dark box. Reducing the hole tightens the image within a certain range, but it admits less light, so the exposure takes longer; if the hole becomes too small, diffraction softens the image again.

Can I make a pinhole camera myself?

Yes. A pinhole camera can work with three elements: a light-tight box, a pinhole and a light-sensitive surface. The precision of the aperture and the exclusion of stray light are essential to a stable image.

What is the difference between a camera obscura and a pinhole camera?

A camera obscura projects the scene outside onto a surface inside a darkened room or box, and some versions use a lens. A pinhole camera forms its image through a small hole instead of a lens. Size alone does not distinguish the two.

Why do pinhole photographs look soft?

With a larger aperture, light from multiple directions overlaps and softens the image. Reducing the aperture tightens the image within a certain range, but an aperture that is too small introduces diffraction and softens it again. A small aperture also admits less light, requiring a longer exposure and increasing the effect of movement.