Definition of parallax in US English:



  • 1The effect whereby the position or direction of an object appears to differ when viewed from different positions, e.g. through the viewfinder and the lens of a camera.

    • ‘Other achievements of Aepinus include improvements to the microscope, and his demonstration of the effects of parallax in the transit of a planet across the Sun's disk.’
    • ‘The actual contact times for any given observer may differ by up to 7 minutes due to the effects of parallax.’
    • ‘Each element was then centered in the lens to decrease distortion from lens curvature or parallax.’
    • ‘An improved configuration uses a splitter mirror to eliminate the effects of parallax but not the differences in lenses.’
    • ‘It is easier to see the effect of parallax the closer the foreground object is to you.’
    1. 1.1 The angular amount of parallax in a particular case, especially that of a star viewed from different points in the earth's orbit.
      • ‘Read Eco's novel, which is full of Paris meridians, lunar parallaxes, the moons of Jupiter, and the Powder of Sympathy.’
      • ‘To measure the parallax, Bradley intended to make a series of observations, noticing how it moved against the background.’
      • ‘Their parts evolve in a kinetic parallax of curves and angles that create a shifting perceptual spectacle.’
      • ‘The work on double stars had been undertaken as a continuation of his father's work which attempted to measure the parallax of a star.’
      • ‘He also gives the tables of the longitudinal and latitudinal parallaxes for certain geographical latitudes, tables of eclipses, and tables of the visibility of the moon.’


Late 16th century (also in the general sense ‘fact of seeing wrongly’): from French parallaxe, from Greek parallaxis ‘a change’, from parallassein ‘to alternate’, based on allassein ‘to exchange’ (from allos ‘other’).