The Human Eye : Main Characteristics of the Sight (2)
Total 15M pixels over the FOV of 4/3PI steradians, most dense in fovea. (about
1/3rd of a full sphere : 4PI steradian)
Visual Acuity : between 30” to 2’ of angle ... let's memorize
1'
Pixel resolution
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28 seconds of arc - highest resolution
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50 seconds of arc - "20/20" vision
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1.5 arc - minutes - "20/30" acceptable vision
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Lighty slot on Black Backgroung : 30'' of arc
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2 lighty spots on Black Background 1 ' of arc
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2 black spot on white background 2 ' of arc
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1 ' : 0.1mn at 35 cm (0.0001/tan(1/60) = 0.34)
A screen at 35 cm, 25 cm, with a 40° FOV should have 2500 pixels (and
not only 1024) !
Stereoscopique Acuity : around 0.1 milliradian : Delta r = 0.001 . r2 (in
m)
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1mm at a distance of 1 m
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0.1 m at a distance of 10 m
Maximim perceptible frequency : 25-30 hz
It is easier to perceive a slight difference than an absolute value
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Abslolute colour vs. comparaison of two colours
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Perception of a distance vs comparaison of the depth of two close object
(within the fov)
What we "look at" is not about a simple picture printed on the retina
Before 70 philosophical (Kant) duality/separation between perception and interpretation
(eye/cortex)... now, more complex organisation, with specialised aera (frequency
perception, color contraste, color and low resolution intensities, move and
stereoscopic depth perception ...)
Average IPD (InterPupillary Distance) : 65 mm for adulte
(between 50 and 70mm for european population)
The center-to-center distance between an adult person's
eyes averages. The binocular and of course HMD, should be capable of any setting
between those two measurements.