What is the Dynamic Range of the CP5000? Human Eye?

I was taking some landscape photos with my Nikon CoolPix 5000 the

other day and nitcied that i was missing certain mountains in the LCD

screen which i could see with the eye. I automaticaaly attributed this

to lack of Dynamic range. This led me to wonder, What is the dynamic

range of the Nikon CoolPix 5000? Also, What is the dynamic range of

the eye? Thanks

Justin,

I'm not sure what the dynamic range of the human eye is, or how you'd even measure it. I'll try to reach for an answer. For the benefit of those who don't know, the human retina has two types of photosensitive cells. Rods are sensitive to luminosity and are found over all parts of the retina except the macula where your eye focuses for detail. They have a wide range of sensitivity, and are responsible for night vision. Thus at night, you don't appreciate colour, and you can't really see something you look at directly.

The macula only has cones. Cones are sensitive to colour. They require more light to be active but are sensitive to a much wider range of light than film or CCDs. Basically, if you can read, you're using cones to do that task.

However, since you can only focus on one area at a time, you won't really notice detail in the other areas. So the dynamic range of the human eye could be considered very limited in that respect.

I'm not sure if I've clarified or confused the situation, but that is my limited understanding of the subject.

I'm still a PS neophyte. Rods see luminosity and some contrast. Cones see in RGB. Cones are about 300 times less sensitive to light than rods. According to Guyton's textbook of physiology, the human eye can change it's sensitivity to light by as much as 500,000 - 1,000,000 times. It's an interesting topic - wonder when we'll have biologic sensors in our cameras?

Jon

I'm still a PS neophyte. Rods see luminosity and some contrast. Cones see in RGB. Cones are about 300 times less sensitive to light than rods. According to Guyton's textbook of physiology, the human eye can change it's sensitivity to light by as much as 500,000 - 1,000,000 times. It's an interesting topic - wonder when we'll have biologic sensors in our cameras?

Jon

anno, I think genually they would say we see in LCH, because that arranges colors in the hue angle, a more logical circular arrangement for us to contemplate when not investigating our navels.

Similar to L*A*B* of course, but different representation of hue and chroma.

I used to know these dynamic ranges off the top of my head. Now I don't remember. It's a big range though, maybe crappy digis are 100:1, film is 1000to3000:1 and in good light the eye is 10000:1. Something like that but probably nowhere near those. If I find it in any of my books and nobody else has beat me to it I'll post it.

"Can a Human See a Single Photon?<br>

The human eye is very sensitive but can we see a single photon? The answer is that the sensors in the retina can respond to a single photon. However, neural filters only allow a signal to pass to the brain to trigger a conscious response when at least about five to nine arrive within less than 100 ms. If we could consciously see single photons we would experience too much visual "noise" in very low light, so this filter is a necessary adaptation, not a weakness."

<a href="http://www.desy.de/pub/www/projects/Physics/ParticleAndNuclear/see_a_photon.html

" ><b><u> Quotation from this link.</b></u> </a><br><br>

I don't know what the upper limit of light intensity is before blindness would result.