Graphic PIZiadas

Graphic PIZiadas

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Vs Iris Diaphragm in photography

diafragmaThe human eye is capable of modifying its geometry to suit the lighting conditions. The iris is responsible for limiting the amount of light reaching our retina.

In photography there is a mechanical device called the diaphragm that functions iris. By combining the speed diaphragm shutter opening, obtain a depth of field.

The iris, in anatomy, is the circular colored membrane and eye separating anterior chamber the posterior chamber. It has a central opening of variable size that connects the two chambers: the pupil.(W)

Cameras in the first diaphragm was a small hole on a metal plate. Currently there are different mechanical solutions to perform this function, although the proliferation of digital cameras can eventually make them disappear.

The diaphragm narrowing is variable by means of a thin sheet which, located between the objective lens , can adjust the amount of light that enters the camera. Typically a disk or fin system provided in a camera lens in a manner that restricts the passage of the light, adjustably generally. The progressive changes in aperture are specified using the number f, which is the ratio between the focal length and effective aperture diameter.(W)

An example of diaphragm can be seen in the following video. Rotating the metal plates to vary the geometry, varying the diameter of the device and thus limiting to a greater or lesser extent the passage of light

mechanical iris test

This mechanism is capable of being used in various applications, such as a window or a building mobile cover. In the following example we can see its use in the door “Nautilus”, el submarine imagined by Jules Verne.

Nautilus Door (iris peephole detail)

As an application we find the unique locking system central table, allowing a small bar hidden inside

Toby Howes’ drinks cabinet Iris opening. Iris was inspired by an antique circular table by Robert Jupe. The body is made from 24 shaped oak slats, the top from burr oak and the black sections from lacquered MDF. Design is copyright Toby Howes.

Toby Howes’ Iris drinks cabinet