6 ms·

I quoted Apple's Retina claim on the site: ‘The Retina display’s pixel density is so high, your eye is unable to distinguish individual pixels’. (They have many

by 1as 13y ago

I quoted Apple's Retina claim on the site: ‘The Retina display’s pixel density is so high, your eye is unable to distinguish individual pixels’. (They have many variations on this). So for me a real retina display would make a single white pixel on black background invisible at normal viewing distances to a normal eye.

ISL 13y ago
By that logic, because the diffraction limit of the human eye is orders of magnitude away from being able to image a star, we cannot see stars. For resolution, the question might be better stated: Can you tell the difference between a) ** and b) * * The two images have the same aggregate intensity, but different morphology. The ancients played the same game as a vision test with stars: http://en.wikipedia.org/wiki/Mizar_and_Alcor http://en.wikipedia.org/wiki/Mizar_and_Alcor
- 1as 13y ago
  Very interesting – thanks.
Someone 13y ago
That may be the case for you, but in vision research, people measure spatial acuity differently. For examples, see http://webvision.med.utah.edu/book/part-viii-gabac-receptors/visual-acuity/ http://webvision.med.utah.edu/book/part-viii-gabac-receptors.... A main reason why your definition isn't used much is because it is highly dependent on the relative brightness of the dot and its background. You can see a dot that has a millionth of the area of an iPad pixel, as long as it radiates the same number of photons on your retina [edit, make that a thousandth or so. Something a million times as bright might kill the cell it lands on before it can send out a signal. http://www.displaymate.com/iPad_ShootOut_1.htm#Backlight_Power http://www.displaymate.com/iPad_ShootOut_1.htm#Backlight_Pow... claims 7W for an ipad backlight; that's over 2W for a million pixels. You wouldn't want to shine a 2W laser into your eye. If you don't believe that, google 2W laser pointer on YouTube] Landolt C's may be a bit tricky to get right on a web page, but you might try and code a staircase experiment (http://en.wikipedia.org/wiki/Psychophysics#Staircase_procedures http://en.wikipedia.org/wiki/Psychophysics#Staircase_procedu...) with illiterate E's.
- 1as 13y ago
  Awesome, that's really clear. Thanks.

by 1as 13y ago

ISL 13y ago

By that logic, because the diffraction limit of the human eye is orders of magnitude away from being able to image a star, we cannot see stars. For resolution, the question might be better stated: Can you tell the difference between a) ** and b) * * The two images have the same aggregate intensity, but different morphology. The ancients played the same game as a vision test with stars: http://en.wikipedia.org/wiki/Mizar_and_Alcor http://en.wikipedia.org/wiki/Mizar_and_Alcor

1as 13y ago
Very interesting – thanks.

Someone 13y ago

That may be the case for you, but in vision research, people measure spatial acuity differently. For examples, see http://webvision.med.utah.edu/book/part-viii-gabac-receptors/visual-acuity/ http://webvision.med.utah.edu/book/part-viii-gabac-receptors.... A main reason why your definition isn't used much is because it is highly dependent on the relative brightness of the dot and its background. You can see a dot that has a millionth of the area of an iPad pixel, as long as it radiates the same number of photons on your retina [edit, make that a thousandth or so. Something a million times as bright might kill the cell it lands on before it can send out a signal. http://www.displaymate.com/iPad_ShootOut_1.htm#Backlight_Power http://www.displaymate.com/iPad_ShootOut_1.htm#Backlight_Pow... claims 7W for an ipad backlight; that's over 2W for a million pixels. You wouldn't want to shine a 2W laser into your eye. If you don't believe that, google 2W laser pointer on YouTube] Landolt C's may be a bit tricky to get right on a web page, but you might try and code a staircase experiment (http://en.wikipedia.org/wiki/Psychophysics#Staircase_procedures http://en.wikipedia.org/wiki/Psychophysics#Staircase_procedu...) with illiterate E's.

1as 13y ago
Awesome, that's really clear. Thanks.