Diaphragm (optics)
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In optics, a diaphragm is a thin opaque structure with an opening at its center. The role of the diaphragm is to stop the passage of light, except for the light passing through the aperture. Thus it i
Pentacon 2.8/135 lens with 15-blade iris
Aperture mechanism of Canon 50mm f/1.8 II lens, with five blades
In the human eye, the iris (light brown) acts as the diaphragm and continuously constricts and dilates its aperture (the pupil)
Diffraction spike
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Diffraction spikes are lines radiating from bright light sources, causing what is known as the starburst effect or sunstars in photographs and in vision. They are artifacts caused by light diffracting
Diaphragm (optics)
…improve the roundness of the iris opening. In a photograph, the number of blades that the iris diaphragm has can be guessed by counting the number of diffraction spikes converging from a light source or bright reflection. For an odd number of blades, there are twice as many spikes as there are blades. In case of an…
Diffraction spikes from various stars seen on an image taken by the Hubble Space Telescope
The optics of a Newtonian reflector telescope with four spider vanes supporting the secondary mirror.
The first JWST deep field with diffraction spikes
JWST image of star cluster Westerlund 1 with diffraction spikes