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Talbot-Plateau Law
The Talbot-Plateau law is an experimental observation related to the psychophysics of vision. If a light flickers so rapidly that it appears as continuous, then its perceived brightness will be determined by the relative periods of light and darkness: the longer the darkness, the weaker the light. The law was first reported in a 1830 article by the Belgian scientist Joseph Plateau. This article stimulated the English photography pioneer Henry Fox Talbot William Henry Fox Talbot FRS FRSE FRAS (; 11 February 180017 September 1877) was an English scientist, inventor, and photography pioneer who invented the salted paper and calotype processes, precursors to photographic processes of the later ... to publish, in 1834, his own observations on this topic made back in the 1820s. While both scientists have followed each other's experiments, they maintained that they conceived the original idea independently. In 1863, the experiments of A. Fick suggested that the Talbot-Plateau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psychophysics
Psychophysics quantitatively investigates the relationship between physical stimuli and the sensations and perceptions they produce. Psychophysics has been described as "the scientific study of the relation between stimulus and sensation" or, more completely, as "the analysis of perceptual processes by studying the effect on a subject's experience or behaviour of systematically varying the properties of a stimulus along one or more physical dimensions". ''Psychophysics'' also refers to a general class of methods that can be applied to study a perceptual system. Modern applications rely heavily on threshold measurement, ideal observer analysis, and signal detection theory. Psychophysics has widespread and important practical applications. For example, in the study of digital signal processing, psychophysics has informed the development of models and methods of lossy compression. These models explain why humans perceive very little loss of signal quality when audio and video sign ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Perception
Visual perception is the ability to interpret the surrounding environment through photopic vision (daytime vision), color vision, scotopic vision (night vision), and mesopic vision (twilight vision), using light in the visible spectrum reflected by objects in the environment. This is different from visual acuity, which refers to how clearly a person sees (for example "20/20 vision"). A person can have problems with visual perceptual processing even if they have 20/20 vision. The resulting perception is also known as vision, sight, or eyesight (adjectives ''visual'', ''optical'', and ''ocular'', respectively). The various physiological components involved in vision are referred to collectively as the visual system, and are the focus of much research in linguistics, psychology, cognitive science, neuroscience, and molecular biology, collectively referred to as vision science. Visual system In humans and a number of other mammals, light enters the eye through the cornea and is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flicker Fusion Threshold
The flicker fusion threshold, critical flicker frequency (CFF) or flicker fusion rate, is a concept in the psychophysics of vision. It is defined as the frequency at which an intermittent light stimulus appears to be completely steady to the average human observer. A traditional term for flicker fusion is "persistence of vision", but this has also been used to describe positive afterimages or motion blur. Although flicker can be detected for many waveforms representing time-variant fluctuations of intensity, it is conventionally, and most easily, studied in terms of sinusoidal modulation of intensity. There are seven parameters that determine the ability to detect the flicker: # the frequency of the modulation; # the amplitude or depth of the modulation (i.e., what is the maximum percent decrease in the illumination intensity from its peak value); # the average (or maximum—these can be inter-converted if modulation depth is known) illumination intensity; # the wavelength (or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Plateau
Joseph Antoine Ferdinand Plateau (14 October 1801 – 15 September 1883) was a Belgian physicist and mathematician. He was one of the first people to demonstrate the illusion of a moving image. To do this, he used counterrotating disks with repeating drawn images in small increments of motion on one and regularly spaced slits in the other. He called this device of 1832 the phenakistiscope. Biography Plateau was born in Brussels. His father, Antoine Plateau ( fr) born in Tournai, was a talented flower painter. At the age of six, the younger Plateau already could read, making him a child prodigy in those times. While attending primary school, he was particularly impressed by a lesson of physics; enchanted by the experiments he observed, he vowed to discover their secrets someday. Plateau spent his school holidays in Marche-les-Dames, with his uncle and his family; his cousin and playfellow was Auguste Payen, who later became an architect and the principal designer of the Belgian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Fox Talbot
William Henry Fox Talbot FRS FRSE FRAS (; 11 February 180017 September 1877) was an English scientist, inventor, and photography pioneer who invented the salted paper and calotype processes, precursors to photographic processes of the later 19th and 20th centuries. His work in the 1840s on photomechanical reproduction led to the creation of the photoglyphic engraving process, the precursor to photogravure. He was the holder of a controversial patent that affected the early development of commercial photography in Britain. He was also a noted photographer who contributed to the development of photography as an artistic medium. He published '' The Pencil of Nature'' (1844–46), which was illustrated with original salted paper prints from his calotype negatives and made some important early photographs of Oxford, Paris, Reading, and York. A polymath, Talbot was elected to the Royal Society in 1831 for his work on the integral calculus, and researched in optics, chemistry, ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broca-Sulzer Effect
The Broca-Sulzer effect or Broca-Sulzer phenomenon is an experimental observation related to the psychophysics of vision. It has two parts, temporal and spatial. In the temporal effect, the perceived brightness of a single flash of light first increases with the flash duration, then reaches a maximum, and decreases for a longer pulse. The maximum is more pronounced and is observed at shorter durations for a stronger illumination; it is reached at approximately 0.1 for a 100 lux flash. Similarly, in the spatial Broca-Sulzer effect, the perceived brightness increases with increasing angular size of the flashing object until it reaches approximately 2.5 arcminutes, and then decreases for a larger object. The Broca-Sulzer effect was reported by André Broca and David Émile Sulzer in 1902. It conflicted with the 1885 report by Adolphe-Moïse Bloch who believed that the perceived brightness monotonously increases with the flash duration. Later research showed that while the Bloch's law ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
