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Can anyone link to a photo of the sky taken from such a location which doesn't have HDR cranked to an 11.

joemi 5y ago
Different cameras have different dynamic ranges (pro cameras can have much higher dynamic ranges than an iphone or even a consumer DSLR), so what dynamic range do you find acceptable? (Also it's pretty hard to show via a digital image what your naked eye would see, since the eye has a high dynamic range.)
- mgraczyk 5y ago
  HDR isn't just about the range of the camera. It's about the range compression used to go from the original light intensity to the 8-bit JPEG rendered in your browser. The image in the article has very aggressive, nonphysical tone mapping. If they didn't, the bottom of the scene would be black. https://en.wikipedia.org/wiki/Tone_mapping https://en.wikipedia.org/wiki/Tone_mapping
- MrStonedOne 5y ago
deleted 5y ago
[deleted]
dheera 5y ago
I do a lot of astrophotography in California mostly -- https://instagram.com/dheeranet/ https://instagram.com/dheeranet/ That said, cameras are inherently much more sensitive to the naked eye, and if you expose for even a few seconds you'll get an image that is far more than your eye can see, let alone hours which are normal for astrophotography. To add to that, your monitor only has about 8 bits of dynamic range, which is far less than your eye has, so it's not really possible to represent an image on a monitor exactly like it looks to the eye. You'll end up with a lot of black pixels or a lot of white pixels. It's not really possible to describe what the sky looks like to the eye using photographs. If you're US-based, I'd really recommend a trip to a dark sky national park such as Death Valley, Lassen, or even Pinnacles.
- kurthr 5y ago
  I agree with you, but it's important to note that the 8 bits of dynamic range are not in constant luminance steps. The gamma of most monitors is about 2 (1.8-2.2) or square law. This is done to roughly match your eye's sensitivity. So those bits have a range of about 64,000,000:1 in brightness. What your monitor can do?? Well, that depends a lot on your monitor and the background illumination of the room.
- 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.

Different cameras have different dynamic ranges (pro cameras can have much higher dynamic ranges than an iphone or even a consumer DSLR), so what dynamic range do you find acceptable? (Also it's pretty hard to show via a digital image what your naked eye would see, since the eye has a high dynamic range.)

mgraczyk 5y ago
HDR isn't just about the range of the camera. It's about the range compression used to go from the original light intensity to the 8-bit JPEG rendered in your browser. The image in the article has very aggressive, nonphysical tone mapping. If they didn't, the bottom of the scene would be black. https://en.wikipedia.org/wiki/Tone_mapping https://en.wikipedia.org/wiki/Tone_mapping
MrStonedOne 5y ago

deleted 5y ago

[deleted]

dheera 5y ago

I do a lot of astrophotography in California mostly -- https://instagram.com/dheeranet/ https://instagram.com/dheeranet/ That said, cameras are inherently much more sensitive to the naked eye, and if you expose for even a few seconds you'll get an image that is far more than your eye can see, let alone hours which are normal for astrophotography. To add to that, your monitor only has about 8 bits of dynamic range, which is far less than your eye has, so it's not really possible to represent an image on a monitor exactly like it looks to the eye. You'll end up with a lot of black pixels or a lot of white pixels. It's not really possible to describe what the sky looks like to the eye using photographs. If you're US-based, I'd really recommend a trip to a dark sky national park such as Death Valley, Lassen, or even Pinnacles.

kurthr 5y ago
I agree with you, but it's important to note that the 8 bits of dynamic range are not in constant luminance steps. The gamma of most monitors is about 2 (1.8-2.2) or square law. This is done to roughly match your eye's sensitivity. So those bits have a range of about 64,000,000:1 in brightness. What your monitor can do?? Well, that depends a lot on your monitor and the background illumination of the room.
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.