TheInfoList

A pinhole camera is a simple camera without a lens but with a tiny
aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of ray (optics), rays that come to a focus (optics), focus ...

(the so-called ''
pinhole A hole is an opening in or through a particular medium, usually a solid body. Holes occur through natural and artificial processes, and may be useful for various purposes, or may represent a problem needing to be addressed in many fields of engi ...
'')—effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects an inverted image on the opposite side of the box, which is known as the
camera obscura A camera obscura (plural ''camerae obscurae'' or ''camera obscuras'', from Latin , "dark chamber") is a darkened room with a small hole or lens at one side through which an image is projected onto a wall or table opposite the hole. "Camera obs ...

effect.

# History

## Camera obscura

The camera obscura or pinhole image is a natural optical phenomenon. Early known descriptions are found in the Chinese
Mozi Mozi (; ; Latinized Latinisation or Latinization can refer to: * Latinisation of names, the practice of rendering a non-Latin name in a Latin style * Latinisation in the Soviet Union, the campaign in the USSR during the 1920s and 1930s to ...
writings (circa 500 BCE) and the Aristotelian ''
Problems Problem solving consists of using generic or ad hoc methods in an orderly manner to find solutions to problems. Some of the problem-solving techniques developed and used in philosophy, artificial intelligence, computer science, engineering, ma ...
'' (circa 300 BCE – 600 CE).
Ibn al-Haytham Ḥasan Ibn al-Haytham (Latinized Latinisation or Latinization can refer to: * Latinisation of names, the practice of rendering a non-Latin name in a Latin style * Latinisation in the Soviet Union, the campaign in the USSR during the 1920s and ...

(965–1039), an
Arab physicist The Arabs (singular Arab ; singular ar, عَرَبِيٌّ, ISO 233: , Arabic pronunciation: , plural ar, عَرَبٌ, ISO 233: , Arabic pronunciation: ) are an ethnic group mainly inhabiting the Arab world. In modern usage the term refers to ...
also known as Alhazen, described the camera obscura effect. Over the centuries others started to experiment with it, mainly in dark rooms with a small opening in shutters, mostly to study the nature of light and to safely watch
solar eclipse A solar eclipse occurs when a portion of the Earth Earth is the third planet from the Sun and the only astronomical object known to harbour and support life. 29.2% of Earth's surface is land consisting of continents and islands. The r ...

s.
Giambattista Della Porta Giambattista della Porta (; 1535 – 4 February 1615), also known as Giovanni Battista Della Porta, was an Italians, Italian scholar, polymath and playwright who lived in Naples at the time of the Scientific Revolution and Protestant Reformation, ...

wrote in 1558 in his
Magia Naturalis ' (in English, ''Natural Magic'') is a work of popular science Popular science (also called pop-science or popsci) is an interpretation of science Science () is a systematic enterprise that Scientific method, builds and organizes knowl ...
about using a concave mirror to project the image onto paper and to use this as a drawing aid. However, at about the same time, the use of a lens instead of a pinhole was introduced. In the 17th century, the camera obscura with a lens became a popular drawing aid that was further developed into a mobile device, first in a little tent and later in a box. The
photographic Photography is the art, application, and practice of creating durable images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employed i ...

camera, as developed early in the 19th century, was basically an adaptation of the box-type camera obscura with a lens. The term "pin-hole" in the context of optics was found in James Ferguson's 1764 book ''Lectures on select subjects in mechanics, hydrostatics, pneumatics, and optics''.

## Early pinhole photography

The first known description of pinhole photography is found in the 1856 book ''The Stereoscope'' by Scottish inventor
David Brewster Sir David Brewster KH PRSE FRS FRS may also refer to: Government and politics * Facility Registry System, a centrally managed Environmental Protection Agency database that identifies places of environmental interest in the United States * F ...

, including the description of the idea as "a camera without lenses, and with only a pin-hole". Sir
William Crookes Sir William Crookes (; 17 June 1832 – 4 April 1919) was a British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** ...
and
William de Wiveleslie Abney Sir William de Wiveleslie Abney (24 July 1843 – 3 December 1920) was an English astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They ...

were other early photographers to try the pinhole technique.

## Film and integral photography experiments

According to inventor
William Kennedy Dickson William Kennedy-Laurie Dickson (3 August 1860 – 28 September 1935) was a Scottish inventor who devised an early motion picture camera A movie camera, film camera or cine-camera is a type of photographic camera which takes a rapid sequence ...
, the first experiments directed at moving pictures by
Thomas Edison Thomas Alva Edison (February 11, 1847October 18, 1931) was an American inventor and businessman. He developed many devices in fields such as electric power generation Electricity generation is the process of generating electric power from s ...

and his researchers took place around 1887 and involved "microscopic pin-point photographs, placed on a cylindrical shell". The size of the cylinder corresponded with their
phonograph A phonograph, in its later forms also called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910) or since the 1940s called a record player, is a device for the mechanical and analogue recording and reproduction ...

cylinder as they wanted to combine the moving images with sound recordings. Problems arose in recording clear pictures "with phenomenal speed" and the "coarseness" of the photographic emulsion when the pictures were enlarged. The microscopic pin-point photographs were soon abandoned. In 1893 the
Kinetoscope The Kinetoscope is an early motion-picture exhibition device. The Kinetoscope was designed for films to be viewed by one individual at a time through a peephole A peephole, peekhole, spyhole, doorhole, magic mirror or door viewer, is a s ...

was finally introduced with moving pictures on celluloid film strips. The camera that recorded the images, dubbed ''Kinetograph'', was fitted with a lens. Eugène Estanave experimented with integral photography, exhibiting a result in 1925 and publishing his findings in ''La Nature''. After 1930 he chose to continue his experiments with pinholes replacing the lenticular screen.

# Usage

The image of a pinhole camera may be projected onto a translucent screen for a real-time viewing (used for safe observation of solar eclipses) or to trace the image on paper. But it is more often used without a translucent screen for pinhole photography with
photographic film Photographic film is a strip or sheet of transparent film baseA film base is a transparent substrate which acts as a support medium for the photosensitive emulsion An emulsion is a mixture of two or more liquids that are normally Miscibil ...
or photographic paper placed on the surface opposite to the pinhole aperture. A common use of pinhole photography is to capture the movement of the sun over a long period of time. This type of photography is called solarigraphy. Pinhole photography is used for artistic reasons, but also for educational purposes to let pupils learn about, and experiment with, the basics of photography. Pinhole cameras with CCDs (
charge-coupled device A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a ...
s) are sometimes used for
surveillance Surveillance is the monitoring of behavior, many activities, or information for the purpose of information gathering, influencing, managing Management (or managing) is the administration of an organization An organization, or org ...

because they are difficult to detect. Related cameras, image forming devices, or developments from it include Franke's widefield pinhole camera, the pinspeck camera, and the pinhead mirror. Modern manufacturing has enabled the production of high quality pinhole lenses that can be applied to digital cameras; allowing photographers and videographers to achieve the camera obscura effect.

# Characteristics of pinhole camera photography

* As pinhole photographs have nearly infinite
depth of field For many cameras, depth of field (DOF) is the distance between the nearest and the farthest objects that are in acceptably sharp focus in an image. The depth of field can be calculated based on focal length The focal length of an optical ...

, everything appears ''in focus''. * As there's no lens
distortion Distortion is the alteration of the original shape (or other characteristic) of something. In communications Communication (from Latin ''communicare'', meaning "to share" or "to be in relation with") is "an apparent answer to the painful di ...
, wide-angle images remain absolutely rectilinear. * Exposure times are usually long, resulting in motion blur around moving objects and the absence of objects that moved too fast. Other special features can be built into pinhole cameras such as the ability to take double images by using multiple pinholes, or the ability to take pictures in
cylindrical A cylinder (from ) has traditionally been a Solid geometry, three-dimensional solid, one of the most basic of curvilinear geometric shapes. Geometrically, it can be considered as a Prism (geometry), prism with a circle as its base. This traditi ...
or spherical perspective by curving the film plane.

# Construction

Pinhole cameras can be handmade by the photographer for a particular purpose. In its simplest form, the photographic pinhole camera can consist of a light-tight box with a pinhole in one end, and a piece of film or photographic paper wedged or taped into the other end. A flap of cardboard with a tape hinge can be used as a shutter. The pinhole may be punched or drilled using a sewing needle or small diameter bit through a piece of tinfoil or thin aluminum or brass sheet. This piece is then taped to the inside of the light-tight box behind a hole cut through the box. A cylindrical oatmeal container may be made into a pinhole camera. The interior of an effective pinhole camera is black to avoid any reflection of the entering light onto the photographic material or viewing screen. Pinhole cameras can be constructed with a sliding film holder or back so the distance between the film and the pinhole can be adjusted. This allows the
angle of view The angle of view is the decisive variable for the visual perception Visual perception is the ability to interpret the surrounding environment (biophysical), environment through photopic vision (daytime vision), color vision, scotopic visio ...

of the camera to be changed and also the effective
f-stop In optics Optics is the branch of physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of natur ...
ratio of the camera. Moving the film closer to the pinhole will result in a wide angle field of view and shorter exposure time. Moving the film farther away from the pinhole will result in a telephoto or narrow-angle view and longer exposure time. Pinhole cameras can also be constructed by replacing the lens assembly in a conventional camera with a pinhole. In particular, compact 35 mm cameras whose lens and focusing assembly have been damaged can be reused as pinhole cameras—maintaining the use of the shutter and film winding mechanisms. As a result of the enormous increase in
f-number In optics, the f-number of an optical system such as a camera lens is the ratio of the system's focal length to the diameter of the entrance pupil ("clear aperture").Smith, Warren ''Modern Optical Engineering'', 4th Ed., 2007 McGraw-Hill Pro ...
, while maintaining the same exposure time, one must use a fast film in direct sunshine. Pinholes (homemade or commercial) can be used in place of the lens on an SLR. Use with a digital SLR allows metering and composition by trial and error, and is effectively free, so is a popular way to try pinhole photography.

# Selection of pinhole size

Up to a certain point, the smaller the hole, the sharper the image, but the dimmer the projected image. Optimally, the size of the aperture should be 1/100 or less of the distance between it and the projected image. Within limits, a small pinhole through a thin surface will result in a sharper
image resolution Image resolution is the detail an image An image (from la, imago) is an artifact that depicts visual perception Visual perception is the ability to interpret the surrounding environment Environment most often refers to: __NOTOC_ ...
because the projected
circle of confusion In optics Optics is the branch of physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ''phýsis'' 'nature'), , is the natural science that studies matter, its Motion (phy ...
at the image plane is practically the same size as the pinhole. An extremely small hole, however, can produce significant
diffraction Diffraction refers to various phenomena that occur when a wave In physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which r ...

effects and a less clear image due to the wave properties of light. Additionally,
vignetting In photography Photography is the art Art is a diverse range of (products of) human activities Humans (''Homo sapiens'') are the most populous and widespread species of primates, characterized by bipedality, opposable thumbs, ...
occurs as the diameter of the hole approaches the thickness of the material in which it is punched, because the sides of the hole obstruct the light entering at anything other than 90 degrees. The best pinhole is perfectly round (since irregularities cause higher-order diffraction effects) and in an extremely thin piece of material. Industrially produced pinholes benefit from
laser A laser is a device that emits light Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that is visual perception, perceived by the human eye. Visible light is usually defined as h ...

etching, but a hobbyist can still produce pinholes of sufficiently high quality for photographic work. A method of calculating the optimal pinhole diameter was first published by
Joseph Petzval Joseph Petzval (6 January 1807 – 17 September 1891) was a mathematician, inventor, and physicist best known for his work in optics. He was born in the town of Spišská Belá, Szepesbéla in the Kingdom of Hungary (in German: Zipser Bela, now Spi ...

in 1857. The smallest possible diameter of the image point and therefore the highest possible image resolution and the sharpest image are given when: :$d=\sqrt\sqrt=1.41\sqrt$ (Where d is the pinhole diameter, f is the distance from pinhole to image plane or “focal length” and λ is the wavelength of light.) The first to apply
wave theory In historical linguistics Historical linguistics, also termed diachronic linguistics, is the scientific study of language change Language change is variation over time in a language A language is a structured system of communicatio ...
to the problem was
Lord Rayleigh John William Strutt, 3rd Baron Rayleigh, (; 12 November 1842 – 30 June 1919) was a British scientist who made extensive contributions to both theoretical A theory is a rational type of abstract thinking about a phenomenon A phenome ...
in 1891. But due to some incorrect and arbitrary deductions he arrived at: :$d=2\sqrt$ So his optimal pinhole was approximatively 1/3 bigger than Petzval’s. The correct optimum can be found with Fraunhofer approximation of the diffraction pattern behind a circular aperture at: :$d=\sqrt\sqrt=1.562\sqrt$ This may be shortened to: $d=0.0366\sqrt$ (When d and f in Millimeters and λ = 550 nm = 0.00055 mm, corresponding to yellow-green.) For a pinhole-to-film distance of 1 inch or 25.4 mm, this works out to a pinhole of 0.185 mm (185 microns) in diameter. For f= 50 mm the optimal diameter is 0.259 mm. The
depth of field For many cameras, depth of field (DOF) is the distance between the nearest and the farthest objects that are in acceptably sharp focus in an image. The depth of field can be calculated based on focal length The focal length of an optical ...

is basically
infinite Infinite may refer to: Mathematics *Infinite set, a set that is not a finite set *Infinity, an abstract concept describing something without any limit Music *Infinite (band), a South Korean boy band *''Infinite'' (EP), debut EP of American mus ...

, but this does not mean that no optical blurring occurs. The infinite depth of field means that image blur depends not on object distance but on other factors, such as the distance from the aperture to the
film plane A film plane is the surface of an image recording device such as a camera, upon which the lens A lens is a transmissive optical Optics is the branch of physics Physics is the natural science that studies matter, its Elementary pa ...
, the aperture size, the wavelength(s) of the light source, and motion of the subject or canvas. Additionally, pinhole photography can not avoid the effects of
haze Haze is traditionally an atmospheric phenomenon Optical phenomena are any observable events that result from the interaction of light and matter. See also list of optical topics and optics. A mirage is an example of an optical phenomenon ...

. In the 1970s, Young measured the resolution limit of the pinhole camera as a function of pinhole diameter and later published a tutorial in The Physics Teacher. Partly to enable a variety of diameters and focal lengths, he defined two normalized variables: pinhole radius divided by resolution limit, and focal length divided by the quantity ''s''2/λ, where ''s'' is the radius of the pinhole and λ is the wavelength of the light, typically about 550 nm. His results are plotted in the figure. On the left-side of the graph, the pinhole is large, and geometric optics applies; the resolution limit is about 1.5 times the radius of the pinhole. (Spurious resolution is also seen in the geometric-optics limit.) On the right-side, the pinhole is small, and
Fraunhofer diffraction In optics Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of optical instruments, instruments that use or Photodetector, detect it. Optics usually ...
applies; the resolution limit is given by the far-field diffraction formula shown in the graph and now increases as the pinhole is made smaller. In the region of near-field diffraction (or
Fresnel diffraction Augustin-Jean Fresnel ( or ; ; 10 May 1788 – 14 July 1827) was a French civil engineer A civil engineer is a person who practices civil engineering Civil engineering is a Regulation and licensure in engineering, professional engi ...

), the pinhole focuses the light slightly, and the resolution limit is minimized when the focal length ''f'' (the distance between the pinhole and the film plane) is given by ''f'' = ''s''2/λ. At this focal length, the pinhole focuses the light slightly, and the resolution limit is about 2/3 of the radius of the pinhole. The pinhole, in this case, is equivalent to a Fresnel zone plate with a single zone. The value ''s''2/λ is in a sense the natural focal length of the pinhole. The relation ''f'' = ''s''2/''λ'' yields an optimum pinhole diameter d = 2, so the experimental value differs slightly from the estimate of Petzval, above.

# Calculating the f-number and required exposure

The f-number of the camera may be calculated by dividing the distance from the pinhole to the imaging plane (the
focal length The focal length of an optical Optics is the branch of physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior through Spacetime, space ...

) by the diameter of the pinhole. For example, a camera with a 0.5 mm diameter pinhole, and a 50 mm focal length would have an f-number of 50/0.5, or 100 (''f''/100 in conventional notation). Due to the large f-number of a pinhole camera, exposures will often encounter
reciprocity Reciprocity may refer to: Law and trade * Reciprocity (Canadian politics), free trade with the United States of America ** Reciprocal trade agreement, entered into in order to reduce (or eliminate) tariffs, quotas and other trade restrictions on ...
failure. Once exposure time has exceeded about 1 second for film or 30 seconds for paper, one must compensate for the breakdown in linear response of the film/paper to intensity of illumination by using longer exposures. Exposures projected on to modern light-sensitive photographic film can typically range from five seconds up to as much as several hours, with smaller pinholes requiring longer exposures to produce the same size image. Because a pinhole camera requires a lengthy exposure, its shutter may be manually operated, as with a flap made of opaque material to cover and uncover the pinhole.

# Coded apertures

A non-focusing coded-aperture optical system may be thought of as multiple pinhole cameras in conjunction. By adding pinholes, light throughput and thus sensitivity are increased. However, multiple images are formed, usually requiring computer
deconvolution In mathematics Mathematics (from Greek: ) includes the study of such topics as numbers ( and ), formulas and related structures (), shapes and spaces in which they are contained (), and quantities and their changes ( and ). There is no gene ...

.

# Modern day interest in pinhole photography

A revival in popularity has become evident in recent years with the success of Kickstarter crowdfunding campaigns offering a range of pinhole photography products. From a camera crafted from wood to the Pinhole Pro - a sleek lens designed for DSLR and MILC digital cameras - these projects have drawn investment from thousands of enthusiastic backers to raise hundreds of thousands of dollars.

# Natural pinhole phenomenon

A pinhole camera effect can sometimes occur naturally. Small "pinholes" formed by the gaps between overlapping tree leaves will create replica images of the sun on flat surfaces. During an
eclipse ECLiPSe is a software system for the development and deployment of Constraint Programming Constraint programming (CP) is a paradigm for solving combinatorial Combinatorics is an area of mathematics Mathematics (from Ancient Greek, Gr ...

, this produces small crescents in the case of a
partial eclipse An eclipse is an astronomical event that occurs when an astronomical object or spacecraft is temporarily obscured, by passing into the shadow of another body or by having another body pass between it and the viewer. This alignment of three celes ...

, or hollow rings in the case of an
annular eclipse A solar eclipse occurs when a portion of the Earth Earth is the third planet from the Sun and the only astronomical object known to harbour and support life. 29.2% of Earth's surface is land consisting of continents and islands. The ...

.

# Observation

Worldwide Pinhole Photography Day is observed on the last Sunday of April, every year.

# Photographers using the technique

*
Billy Childish Billy Childish (born Steven John Hamper, 1 December 1959) is an English painter, author, poet, photographer, film maker, singer and guitarist. Since the late 1970s, Childish has been prolific in creating music, writing and visual art. He has le ...

* George Davison *
Barbara Ess Barbara Ess (born Barbara Eileen Schwartz; April 4, 1944 – March 4, 2021) was an American photographer. She often used a pinhole camera and was also known for her No Wave musical and editorial work. Education Ess earned a B.A. at the University ...
* Wolf Howard *
Steven Pippin Steven Pippin (born 1960 at Redhill, Surrey) is an English artist. Pippin works with converted or improvised photographic equipment and kinetic sculptures. Early life and education Pippin's work shows a strong interest in the mechanical, which ...
* Jesse Richards

*
Camera obscura A camera obscura (plural ''camerae obscurae'' or ''camera obscuras'', from Latin , "dark chamber") is a darkened room with a small hole or lens at one side through which an image is projected onto a wall or table opposite the hole. "Camera obs ...

(usually employs a lens) * Dirkon *
Henry Fox Talbot William Henry Fox Talbot Fellow of the Royal Society, FRS FRSE Royal Astronomical Society, FRAS (; 11 February 180017 September 1877) was an English scientist, inventor and photography pioneer who invented the Salt print, salted paper and calot ...
*
Ibn al-Haytham Ḥasan Ibn al-Haytham (Latinized Latinisation or Latinization can refer to: * Latinisation of names, the practice of rendering a non-Latin name in a Latin style * Latinisation in the Soviet Union, the campaign in the USSR during the 1920s and ...

*
Nautilus The nautilus (from the Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the power ...

(whose pinhole eye functions as a camera obscura) *
Pinhole camera model . The pinhole camera model describes the mathematical relationship between the coordinate In geometry Geometry (from the grc, γεωμετρία; ''wikt:γῆ, geo-'' "earth", ''wikt:μέτρον, -metron'' "measurement") is, with arithm ...
* Pinhole glasses *
Pinhole occluder A pinhole occluder is an opaque disk with one or more small holes through it, used by ophthalmologist Ophthalmology () is a branch of medicine Medicine is the science Science () is a systematic enterprise that builds and organizes know ...

, a similar device used by ophthalmologists *
Spatial filter A spatial filter is an optical device which uses the principles of Fourier optics to alter the structure of a beam of light or other electromagnetic radiation, typically coherence (physics), coherent laser light. Spatial filtering is commonly used ...
* The Great Picture *
Zone plate A zone plate is a device used to focus Focus, FOCUS, or foci may refer to: Arts * Focus or Focus Festival, former name of the Adelaide Fringe The Adelaide Fringe, formerly Adelaide Fringe Festival, is the world's second-largest annual a ...

# References

* Eric Renner ''Pinhole Photography: From Historic Technique to Digital Application''

pinhole.cz

Pinhole Photography by Vladimir Zivkovic

Worldwide Pinhole Photography Day website

An easy way to convert a DSLR to a pinhole camera

Pinhole Photography and Camera Design Calculators

Illustrated history of cinematography

Oregon Art Beat: Pinhole Photos by Zeb Andrews

Civil War 150 Pinhole Project by Michael Falco
{{DEFAULTSORT:Pinhole Camera Cameras by type Arab inventions