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Suggestion to add an HDR category under Practice and Technique


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My opinion is, there is nothing to like or dislike about HDR. It’s a workaround to address the limited dynamic range of recording devices.

It would be more accurate to say the limited range of display devices and media. Prints are good to about 6 stops, a really good monitor might have 10 stops, whereas a decent camera can capture 13 to 15 stops. Tone mapping is a way to compress that range to fit the medium.

 

HDR is a tool to be used when appropriate, nothing more and nothing less. It takes practice to use correctly, like using a hammer and not bending the nails.

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The fovea of the eye, populated with cone cells, responsible for high resolution for driving and reading as well as color, is approximately 3 square mm, containing about 416 thousand cone cells, or about 0.42 MP. The fovea subtends an angle of approximately 1/2 a degree. Most of the eye is populated by rod cells, which can only sense light, dark and motion, not color nor detail.

 

Any one who has done pixel-peeping of a 24 MP image, taken with a good lens and technique, will see details completely invisible to the eye, even with a normal or wide-angle lens.

 

While the eye can adjust to accommodate light levels from broad daylight to a moonless night, it can't do both at the same time. For a typical situation, the dynamic range of the human eye is approximately 10 stops. None of the spectacular detail in the Milky Way, in a 10 second exposure, is visible to the unaided eye, even on a very dark night. At the average magnitude of 5.2, you are lucky to see even a hazy band in the sky.

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You can't see detail finer than the spacing of cone cells in the retina, and even that is not attainable in practice. In most people, the human eye is definitely a sub-standard lens, which is obvious to anyone undergoing an eye exam. Interpolation is guessing, not seeing.

 

I can see a basket ball and hoop from a 100 yards or more, and I'm no super athlete. Now hitting the hoop is another story, and I give LeBron all the credit for the hand-eye coordination needed to do that. I doubt being chased by Lions makes you a better basketball player. Besides, I though they were a football team.

 

Zoom in enough on an eye's retina and there's your Milky Way...

If only early astronomers kew this they could have saved a lot of time and effort ;) Even Galileo needed a telescope, so he invented one.

 

Information on the physiology of the eye and vision is readily available. It's not as interesting as popular fiction, but definitely more trustworthy.

 

Lions of the Wild Kingdom variety can tun 40 mph, nearly twice as fast as a human sprinter. You can't outrun a lion, so to survive you have to stop and face them with a weapon (or outrun someone slower). A spear can work, but I'd rather have a .375 H&H Magnum (or bigger).

Edited by Ed_Ingold
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,"but I'd rather have a .375 H&H Magnum (or bigger)". Ed.

 

Best with a 44 Magnum don't trust those little bullets...mass vs velocity..

 

"the human eye is definitely a sub-standard lens, which is obvious to anyone" Ed.

 

But that is what we see with our information technology.....in the future maybe we will have bionic eyes then the picture will change and make us more happy..

 

I cannot help just think a bloke takes a photo of his pond in HDR and wets himself cause he has now created a masterpiece...hey ho why not.

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I wouldn't expect a Brit to know more than the basics of firearms. A .375 H&H is the smallest caliber permitted in Africa for dangerous game. It has a velocity of roughly 3000 fps and a 300 grain bullet, delivering up to 5000 ft-lbs of energy. A .44 Magnum is a handgun cartridge with (typically) a 240 grain bullet at at 1400 fps, about 1100 ft-lb. The latter is generally sufficient for large game in the U.S., including mountain lion and an occasional grizzly bear, although the traditional weapon for grizzly is a .375 H&H Magnum. A .44 Mag is still better than a sharp stick in grizzly country.

 

You are probably viewing these images on a computer screen with a dynamic range of 10 stops or less, easily in range of the human eye. It's always good to include a demonstration of what not to do with HDR processing (the red car). Thank you for that.

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We mostly don't do the gun thing in Brit land. But a 44 Magnum was good enough for Dirty Harry I would be happy with one in the badlands;))

 

Are our 44 Magnum loads really capable of handling grizzly?

The answer is yes, in the hands of a reliable shot. From a comparative point of view, our 44 Magnum Hammerheads provide far more penetration than the 300-grain NosIer Partition fired from the 375 Holland & Holland. Also, both bullets present an extremely blunt front end (meplat). Our 44 bullets also offer far greater security from bullet fracture or deflection than any expanding bullet. Since beginning production in 1988 we have had many customers defend themselves from grizzlies, and always our 44 Magnum ammo has provided super-deep penetration, generally to the hips on a frontally shot bear (even when the skull is engaged.)

 

"It's always good to include a demonstration of what not to do with HDR processing. Thank you for that." Ed

 

Hope you are not referring to my old steam engine rather like it.

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You can't see detail finer than the spacing of cone cells in the retina, and even that is not attainable in practice. In most people, the human eye is definitely a sub-standard lens, which is obvious to anyone undergoing an eye exam. Interpolation is guessing, not seeing.

 

I can see a basket ball and hoop from a 100 yards or more, and I'm no super athlete. Now hitting the hoop is another story, and I give LeBron all the credit for the hand-eye coordination needed to do that. I doubt being chased by Lions makes you a better basketball player. Besides, I though they were a football team.

 

 

If only early astronomers kew this they could have saved a lot of time and effort ;) Even Galileo needed a telescope, so he invented one.

 

Information on the physiology of the eye and vision is readily available. It's not as interesting as popular fiction, but definitely more trustworthy.

 

Lions of the Wild Kingdom variety can tun 40 mph, nearly twice as fast as a human sprinter. You can't outrun a lion, so to survive you have to stop and face them with a weapon (or outrun someone slower). A spear can work, but I'd rather have a .375 H&H Magnum (or bigger).

 

Isn't the other part of vision perception? At some point it is all interpolated in the brain. Despite the fact you can't see more accurately than your lens and everything else in the chain, but the other aspects of vision.

Edited by Uhooru
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What is the relationship of vision and perception? According to the philosophy of Empiricism (e.g., "If a tree falls..."), only perception counts, the way your consciousness processes physical data from the senses. Sometimes the rules of perception can be defined objectively. A baseball player moves to a position where the ball maintains a constant angle in the sky, whether by intuition or training. Navigators know that if another ship maintains a constant azimuth, you are on a collision course, regardless of speed and bearing. That principle works pretty well for cars converging at an on-ramp too. Is vision perfect? How many people wear glasses or contacts? Are these "extensions" of the eye, or augmentations? In astronomy, the human eye can distinguish objects as close as abut 30 arc-seconds apart. The average iris is 6 mm wide, and can gather only so much light. With a telescope, you can magnify the resolution to about 2 arc-seconds before atmospheric disturbance prevail. An 8" telescope gathers about 16 stops more light than the unaided eye.

 

I just had cataract surgery, so I am acutely aware of the limitations of human vision, including color.

 

Photography is no different. You tend to like images that resemble what you remember, not necessarily what actually was. Grass should be green, the sky blue or distinctly cloudy. Who would pay for a portrait that didn't improve on the flaws everyone has, but conveniently ignore in the mirror? HDR is one of the tools you can use to restore the perception of a scene you liked, as you remember it.

 

("Interpreted" would be a better word than "interpolated," in this context)

Edited by Ed_Ingold
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Photography is no different. You tend to like images that resemble what you remember, not necessarily what actually was.

I like snapshots that resemble what I remember and I like a lot of other kinds of photos that give new insights or different perspectives on what I remember or send me into unknowns of the future - photography is about perception and so much more.

Edited by The Shadow
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