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A 16th-century engraving of Ptolemy. Ptolemy's Optics is a 2nd-century book on geometrical optics, dealing with reflection, refraction, and colour. The book was most likely written late in Ptolemy's life, after the Almagest, during the 160s. [1] The work is of great importance in the early history of optics. The Greek text has been lost completely.
Persistence of vision is the optical illusion that occurs when the visual perception of an object does not cease for some time after the rays of light proceeding from it have ceased to enter the eye. [1] The illusion has also been described as "retinal persistence", [2] "persistence of impressions", [3] simply "persistence" and other variations ...
Paradox illusions (or impossible object illusions) are generated by objects that are paradoxical or impossible, such as the Penrose triangle or impossible staircase seen, for example, in M. C. Escher's Ascending and Descending and Waterfall. The triangle is an illusion dependent on a cognitive misunderstanding that adjacent edges must join.
The Hering illusion (1861): When two straight and parallel lines are presented in front of radial background (like the spokes of a bicycle), the lines appear as if they were bowed outwards. Hollow-Face illusion: The Hollow-Face illusion is an optical illusion in which the perception of a concave mask of a face appears as a normal convex face.
Ptolemy attempted to explain the Moon illusion through atmospheric refraction in the Almagest, and later (in the Optics) as an optical illusion due to apparent distance, [7] [8] or the difficulty of looking upwards, although interpretations of the account in the Optics are disputed. [9]
The wagon-wheel effect (alternatively called stagecoach-wheel effect) is an optical illusion in which a spoked wheel appears to rotate differently from its true rotation. The wheel can appear to rotate more slowly than the true rotation, it can appear stationary, or it can appear to rotate in the opposite direction from the true rotation ...
Phantograms, also known as Phantaglyphs, Op-Ups, free-standing anaglyphs, levitated images, and book anaglyphs, are a form of optical illusion.Phantograms use perspectival anamorphosis to produce a 2D image that is distorted in a particular way so as to appear, to a viewer at a particular vantage point, three-dimensional, standing above or recessed into a flat surface.
This was a variation of the thaumatrope. It had a card with pictures "painted in two different positions on both sides". This card was placed in the two-part mahogany holder with a handle and a brass pin that would semi-rotate the card when it was twirled (a bit of iron preventing full rotation).