I recent­ly came across a very curi­ous cube cam­era. With­out a viewfind­er, mode selec­tion, and even with­out a focus ring. And the size is quite mod­est: if desired, the Lytro ILLum will even fit into your pock­et. The baby’s sen­sor is able to read vec­tor infor­ma­tion about the light at each point. This means that this cam­era allows you to select or change the focus point after shoot­ing. It is curi­ous that the devel­op­ment of tech­nol­o­gy has returned to its orig­i­nal point — a cam­era with­out a lens.

Ini­tial­ly, a lens was not need­ed, there was no set­tings wheel, and even the cam­era itself, in fact, was not there either. And the pic­ture still came out. It’s about the cam­era obscu­ra.

Image: magisteria.ru

What is it all about?

The cam­era obscu­ra is the sim­plest opti­cal device for obtain­ing an imprint of light, and with it every­thing around that this light will out­line. Almost like shoot­ing with a wide-angle lens, only with­out a lens.

The process of obtain­ing an image in a cam­era obscu­ra is based on the phys­i­cal prop­er­ties of light. In a com­plete­ly dark space (for exam­ple, a square black box), a small diam­e­ter hole is cre­at­ed on one of the planes. As a rule, it does not exceed a cou­ple of mil­lime­ters. The light, and with it the entire expo­sure behind this hole, is pro­ject­ed upside down onto the oppo­site plane to the hole. The image size direct­ly depends on the dis­tance between the hole and the oppo­site plane. And its sharp­ness is direct­ly relat­ed to the diam­e­ter: the small­er it is, the image is sharp­er.

Image: multiurok.ru
Pho­to: photoplay.ru

The prin­ci­ple of oper­a­tion is sim­i­lar to how the human eye works. The image enters the cam­era, just as the envi­ron­ment around us is read by sight: through a small hole (the pupil) and upside down. The light enters the hole at an angle, the rays reflect­ed from the top of the objects go down, and those that are reflect­ed from the objects near the ground rush up. In the dark space of the cam­era, the rays inter­sect and, con­se­quent­ly, the pic­ture is flipped. In our case, the image is turned over by the brain, and in mod­ern cam­eras this hap­pens due to the mir­ror.

Photography without lenses

The prop­er­ty of light to project objects was dis­cov­ered in the Mid­dle Ages. An analy­sis of the physics of light and the first portable cam­era obscu­ra can be found in Da Vin­ci’s draw­ings. Sim­i­lar opti­cal devices are described by many Euro­pean physi­cists and sci­en­tists of that time.

Image: infourok.ru
Pho­to: reddit.com

The portable cam­era obscu­ra, a kind of box with a hole, became wide­spread by the 17th and 18th cen­turies. Sci­en­tists used it for obser­va­tions, artists used it as an aux­il­iary tool, and pho­tog­ra­phers… pho­tog­ra­phers start­ed with it! Crafts­men from the 19th cen­tu­ry fig­ured out how to catch the image pro­ject­ed onto the wall: all you had to do was attach met­al plates coat­ed with a pho­to­sen­si­tive com­po­si­tion. And so pho­tog­ra­phy was born.

Back to the present

The cam­era obscu­ra still exists today. It’s just called Pin­hole.

Pho­to: Lomography.com User: krusty1980
Pho­to: Ste­fan Killen

At the moment of its birth, the pin­hole was a clas­sic cam­era obscu­ra, only with a touch of moder­ni­ty: why big wood­en box­es with pho­to­graph­ic plates when there is 135mm film? Every­thing is much more com­pact and sim­pler. The most ascetic ver­sion of a pin­hole is a match­box cam­era with a film reel and a take-up reel attached. And the role of optics is per­formed by a tiny hole made by a nee­dle on adhe­sive tape.

Such a cam­era can be made from impro­vised mate­ri­als, the main thing is to fix two reels and cal­cu­late the cor­rect dis­tance between frames and the dis­tance from the film to the hole. Of course, expo­sure is also by eye. As a rule, in such cas­es, one frame is exposed from sev­er­al min­utes to sev­er­al hours, depend­ing on the lev­el of light­ing, film and time of day.

Sony Alpha 7R with pro­fes­sion­al pin­hole lens
Pho­to on Sony A7RII with pin­hole lens. Flickr.com User: Dierk
Pho­to on Fuji­film X‑T1 with pin­hole lens

Pin­hole is not lim­it­ed to ana­log pho­tog­ra­phy: your Canon, Nikon, Sony and just about any cam­era can also be fit­ted with a pin­hole lens. And there is always the option to arm your­self with a heat­ed nee­dle and make a hole in the plas­tic plug on the cam­era body. She will become the lens. In the case of dig­i­tal cam­eras, this is much more con­trol over the process, set­tings and a field for exper­i­men­ta­tion. It will be pos­si­ble to look at the result and be sur­prised at the physics of light right away!