Question: According to [DxO tests](http://www.dxomark.com/index.php/Cameras/Camera-Sensor-Ratings/%28type%29/usecase_landscape), cameras have 10 to 12 stops of dynamic range. Is that correct? Noise can completely screw some lowers values (easily resulting in loss of some stops).

Also [Norman Koren says](http://www.normankoren.com/digital_tonality.html) that a digital camera's original dynamic range can be 9 to 11 stops, but prints have "only" 6.5 stops.

In a section on dynamic range, Wikipedia says the human eye has a contrast ratio of around [6.5 stops](http://en.wikipedia.org/wiki/Human_eye#Dynamic_range). If that is the case, why is the human eye clearly much better than cameras to record scenes with high dynamic range?

Answer: 
Metaphorically, it may be due to the fact that the brain doesn't "see" a single image, but composes one based on a series of continuous "shots" from the eyes as they move around the scene.

Each of these "shots" are "taken" with variable "apertures", in order to maximize the overall dynamic range of the final "image".

You can think of the mental process as a mix of a panorama and HDR if you prefer. :o)
This question cannot be standardized because the eye's dynamic range is always shifting to adjust to the intensity of light, not only by the ''human aperture'' but also with the brain's sensitivity to what the eye is looking at. It's like a camera with different processors, using the most sensitive to light when it wants and using the highest sensitivity to dark when it wants. I think the dynamic range of the eye is somewhere around 22 to 24 EV.

I have been intrigued by this question for a while now. Try to take a photo of a milk white exhibition stand with sheets of lightboxes from different angles without having to bracket for exposure and then bracket for white balance separately and then post-processing them later. It is physically impossible.

Just like the eye adjusts to white balance psychologically and that's why the term ''need a fresh eye'' that is because visual perception is also a factor.