4 ms·

Rays of light travel in straight lines. Light enters your eye and hits the back of your retina inverted, not just upside down. Left is right. Up is down. [1] h

Rays of light travel in straight lines. Light enters your eye and hits the back of your retina inverted, not just upside down. Left is right. Up is down. [1] https://www.schoolphysics.co.uk/age11-14/Light/text/Pinhole_camera/index.html https://www.schoolphysics.co.uk/age11-14/Light/text/Pinhole_...

game-of-throws 4y ago
Right, but how is this any different than a camera? Nobody goes around saying Nikon designed their cameras upside down and then had to hack around the mistake in software. It's just how lenses work.
- grupthink 4y ago
  > Right, but how is this any different than a camera? The commenter above argues the image isn't upside down. > Nobody goes around saying Nikon designed their cameras upside down and then had to hack around the mistake in software. It's just how lenses work. That's an oddly specific statement. A camera inverts an image using any combination of lenses, mirrors, and software. And if you were building an eye, you would be meticulously poring over these implementation details and discussing all your options. Should you revert the image by adding another lens? Or, do an inverse affine transformation? Maybe you can cross the optic nerves so that the brain gets the correct image? Or program a reward function to individual neurons guided by the vestibular system... etc. The screen you are looking at right now has gone through at least two transformations - due to the physical nature of light. The fact that you can look around and not realize all this is happening is pretty amazing. There are a few leaky abstractions as noted in the twitter thread.
  - mattgperry 4y ago
    No - if you were creating a lens or sensor you wouldn't even think about the orientation of the image relative to the real world. It's irrelevant - only that the pixels can be read off in an orderly manner. This is even true for analogue processes (but if the method of converting negatives to photos was different I can see it'd be a factor). Maybe people in this thread are talking past each other but imo I agree with the commenter arguing that the image is ever "upside down", there is no image.
- fredgrott 4y ago
  Because our brains form true stereo vision processing which requires two images that are combined into one. Digital cameras do not do that, it's ho we get our true depth perception among other features.

game-of-throws 4y ago

Right, but how is this any different than a camera? Nobody goes around saying Nikon designed their cameras upside down and then had to hack around the mistake in software. It's just how lenses work.

grupthink 4y ago
> Right, but how is this any different than a camera? The commenter above argues the image isn't upside down. > Nobody goes around saying Nikon designed their cameras upside down and then had to hack around the mistake in software. It's just how lenses work. That's an oddly specific statement. A camera inverts an image using any combination of lenses, mirrors, and software. And if you were building an eye, you would be meticulously poring over these implementation details and discussing all your options. Should you revert the image by adding another lens? Or, do an inverse affine transformation? Maybe you can cross the optic nerves so that the brain gets the correct image? Or program a reward function to individual neurons guided by the vestibular system... etc. The screen you are looking at right now has gone through at least two transformations - due to the physical nature of light. The fact that you can look around and not realize all this is happening is pretty amazing. There are a few leaky abstractions as noted in the twitter thread.
- mattgperry 4y ago
  No - if you were creating a lens or sensor you wouldn't even think about the orientation of the image relative to the real world. It's irrelevant - only that the pixels can be read off in an orderly manner. This is even true for analogue processes (but if the method of converting negatives to photos was different I can see it'd be a factor). Maybe people in this thread are talking past each other but imo I agree with the commenter arguing that the image is ever "upside down", there is no image.
fredgrott 4y ago
Because our brains form true stereo vision processing which requires two images that are combined into one. Digital cameras do not do that, it's ho we get our true depth perception among other features.