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Human eyes have about 25 stops of computational dynamic range (about 7 stop without the stuff the brain does), cameras only win because they can do crazy long e

by novok 5y ago

Human eyes have about 25 stops of computational dynamic range (about 7 stop without the stuff the brain does), cameras only win because they can do crazy long exposures and are not continuous video cameras like eyes are. And camera's photos are at most 14 stops. I look forward to a world one day where digital cameras can do the full 25 stops without all the computational tricks the human brain does, it's going to be cool! Also looking forward to 10 and 12 bit displays to start becoming standard with the HDR push in consumer video. Maybe one day we will get a 25 stop display too!

throw0101a 5y ago
> Human eyes have about 25 stops of computational dynamic range (about 7 stop without the stuff the brain does), cameras only win because they can do crazy long exposures and are not continuous video cameras like eyes are. That may be true, but your eyes have an aperture of 'only' 7mm (when you're young). That's not a lot of area for photons to get into. Get a pair of cheap 7x35mm (or 7x50mm) binoculars and now the aperture is 5-7 times larger (and the area is more, per πr^2).
doetoe 5y ago
What are these "stops"? Bits?
- dheera 5y ago
  In photography terminology a "stop" is a factor of 2 in brightness. For example if you reduce your aperture to 1/2 the area that's reducing by 1 stop. If you dial your ISO (sensitivity) down from 200 to 100 that's 1 stop. If you reduce your shutter speed by a factor of 2 that's 1 stop. If you make your flash twice as bright that's 1 stop. They're called stops because these controls on a manual camera actually have click-stops. You turn the aperture 3 clicks in one direction and your shutter 3 clicks in the other direction and your image brightness stays the same. Or you turn your ISO 2 clicks in one direction and your flash 2 clicks in the other direction and your image brightness stays the same. Nowadays most modern equipment has click stops at 1/2 stop or 1/3 stop increments depending on the brand. 25 stops of range means the ability to resolve a dynamic range of 1 : 2^25. It's not really bits per se, because the error in measurement also grows with the value, i.e. it can likely resolve the difference between a value of 1 and 2 but it cannot resolve the difference between 2^24+1 and 2^24+2.
  - doetoe 5y ago
    Thanks for your elaborate answer. I had never (consciously) heard the term.

by novok 5y ago

throw0101a 5y ago

> Human eyes have about 25 stops of computational dynamic range (about 7 stop without the stuff the brain does), cameras only win because they can do crazy long exposures and are not continuous video cameras like eyes are. That may be true, but your eyes have an aperture of 'only' 7mm (when you're young). That's not a lot of area for photons to get into. Get a pair of cheap 7x35mm (or 7x50mm) binoculars and now the aperture is 5-7 times larger (and the area is more, per πr^2).

doetoe 5y ago

What are these "stops"? Bits?

dheera 5y ago
In photography terminology a "stop" is a factor of 2 in brightness. For example if you reduce your aperture to 1/2 the area that's reducing by 1 stop. If you dial your ISO (sensitivity) down from 200 to 100 that's 1 stop. If you reduce your shutter speed by a factor of 2 that's 1 stop. If you make your flash twice as bright that's 1 stop. They're called stops because these controls on a manual camera actually have click-stops. You turn the aperture 3 clicks in one direction and your shutter 3 clicks in the other direction and your image brightness stays the same. Or you turn your ISO 2 clicks in one direction and your flash 2 clicks in the other direction and your image brightness stays the same. Nowadays most modern equipment has click stops at 1/2 stop or 1/3 stop increments depending on the brand. 25 stops of range means the ability to resolve a dynamic range of 1 : 2^25. It's not really bits per se, because the error in measurement also grows with the value, i.e. it can likely resolve the difference between a value of 1 and 2 but it cannot resolve the difference between 2^24+1 and 2^24+2.
- doetoe 5y ago
  Thanks for your elaborate answer. I had never (consciously) heard the term.