PSYB51H3 Chapter 3: Chapter 3 Notes
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Contrast: the difference in luminance between an object and the background or between lighter and darker parts of the same object. Acuity: the smallest spatial detail that can be resolved. To scientists, it"s the smallest visual angle of a cycle of the grating that we can perceive. Cycle: one repetition of a black and a white stripe. Visual angle: the angle subtended by an object at the retina. A cycle that subtends an angle of approx 1 minute of arc. Finest high-contrast detail that can be resolved due to spacing of photoreceptors in the retina. Sine wave grating: a grating with a sinusoidal luminance profile. If the stripes are wider than photoreceptors, than you will see gratings; if they"re too narrow you"ll see gray. The white and black part of the grating should each fall on separate cones. Most healthy adults have 20/20 vision (acuity level)
