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3.3: Resolving angle and time

  • Page ID
    128456
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    Performance of the eye, assessed in physical terms. (This and next page.) The ‘pixel spacing’ of photoreceptors and the focal length determine a theoretical geometrical limit for angular resolution: ~0.05, which the eye’s performance sometimes approaches. In bright light with very small pupil, the eye can reach the limit imposed by diffraction (discussed later). Stereo vision contributes to depth perception for close objects. Motion looks smooth at ~ 25 frames per second, suggesting a photoreceptor integration time of tens of ms. Integration time can increase for greater sensitivity, but this loses time resolution. 

    Learning Objectives
    • Pixel geometry and angular resolution.
    • Performance doesn’t usually reach diffraction limit.
    • Integration is tens of ms, hence video frame rates of 25 fps.

     

     

    Table \(\PageIndex{1}\)
    Links to related material  

    The eye: optics, anatomy and accommodation
    The eye and the camera: similarities and differences. Anatomy and focussing. Accommodation and reading glasses. Retinal anatomies. The blind spot. Image formation and analysis.

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    After-images give complementary colour illusions due to retinal fatigue. Complementary colour charts. Demonstration of contrast sensitivity and lateral inhibition.

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    Colour mixing
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    The Eye: performance and compromises
    Photon capture efficiency, aperture and aberration, focal length, integration time/ exposure time/ frames per second, stereoscopic vision, angle of view.

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    Why vision?
    Why is the octave from 400 to 700 nm so important? Why so little UR and IV vision? A comparison of vision and hearing.

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    3.3: Resolving angle and time is shared under a CC BY-NC-ND 4.0 license and was authored, remixed, and/or curated by LibreTexts.

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