Pinhole (optics)
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A pinhole is a small circular hole, as could be made with the point of a pin. In optics, pinholes with diameter between a few micrometers and a hundred micrometers are used as apertures in optical sys
Wide-field micrograph of a damaged 80 μm pinhole
Natural pinholes formed by tree leaves – Solar eclipse of August 21, 2017 in Washington state
Pinhole camera
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A pinhole camera is a simple camera without a lens but with a tiny aperture —effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects an
Pinhole (optics)
…as a low-pass filter for spatial frequencies in the image plane of the beam. A small pinhole can act as a lens, focusing light. This effect is used in pinhole cameras and camera obscura, and in solarigraphy. This effect is also used in pinhole occluders, which are used by ophthalmologists, orthoptists, and optometrists…
A camera with home-made pinhole application
A fire hydrant photographed by a pinhole camera made from a shoe box, exposed on photographic paper to create the negative image (top). The positive image (bottom) was created digitally from the negative image. The length of the exposure was 40 seconds. There is noticeable flaring in the bottom-right corner of the image, likely due to extraneous light entering the camera box.
A home-made pinhole camera (on the left), wrapped in black plastic to prevent light leaks, and related developing supplies
An example of a 20-minute exposure taken with a pinhole camera