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Old Oct 28, 2003, 8:37 AM   #11
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Comparing the eye to the camera (digital or chemical) makes about as much sense as comparing the eye to the elbow. Given the wildly different control mechanisms, it would be arguable to say the eye is much more similar to the elbow than it is to a camera.

To say that they eye captures "true color" is a really short tautology - "true color" is the range of colors that can be discerned by the eye. Cameras have a much wider range, almost infinite if you include radio/X-ray telescopes a kind of specialized camera. Even the basic digicams have their range crippled with an IR filter. So in sense of color range, the eye is vastly inferior to a camera.

Mike_PEAT's comments on low light is a good one. Walking about with a full moon has a very different look than day light. Yet a color photo taken by moon light (easy with a chemical camera) does not look very differnt than a daylight shot. Again, the eye is inferior.
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Old Oct 28, 2003, 9:57 AM   #12
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I'm sorry I got into this to late. From a technical standpoint it's not a great discussion (as Bill Drew points out) but it's still an interesting one.

Some interesting points.

When trying to explain to my girlfriend about a camera and how it differs from what she is used to (i.e. her vision) we did a simple test. Have you and someone else stand about 10-15 feet apart. Have the other person walk slowly towards you (but at a constant rate.) Focus on them as they walk. Describe what happens. Now do it again, but really think about what is happening while it happens. You eye focues very smoothly. The DOF isn't that great (when you're focusing) In some people there is a slight hitch in the foucs where it isn't as smoother for an instant (I never have understood why.) Its really odd. Your vision is something you take for granted... how it works is not something we think much about.

I have been told that your eye can see over 10 f-stops of light shades at once. As was dicusssed earlier this month here, most consumer digital cameras don't capture more than a 3-4.5 f-stop range of light. That is a huge difference. When people talk about seeing like a camera (to help you visualize your shots) this is one of the things they mean.

I personally have experienced seeing in shades of grey (I don't think it was B&W, but it was years ago.) I had to get up at 4:30am to go on a long school field trip. I didn't turn on the light so as to not wake by brother. About 1/2 way through getting dressed, I realized that I didn't know what the color was of the shirt I had just picked out. It was very weird. Since we had just talked about rods/cones in science class a few weeks back (I got lucky) I realized what was going on. But it was very strange.

I have heard some evolutionary biologists talk about our brain as a huge vision system (on NOVA, I believe.) That it is something which are brains are particularly good at. The eye might not be an amazing opical device, but the entire system (from eye to brain) is very good.

Eric
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Old Oct 28, 2003, 11:47 AM   #13
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Quote:
Originally Posted by eric s
... From a technical standpoint it's not a great discussion, but it's still an interesting one. ...
Eric
You hit the point square on.

The point of a photograph is to make an image that is pleasing to the eye. So understanding how they eye works, and how your camera works, can be usefull. But they are only slightly similar in *HOW* they work. One nice article can be found at http://www.cliffshade.com/dpfwiw/vision.htm.

<rant> Though the question of how many megapixels the eye has sounds interesting, it really makes no more sense than asking how many megapixels a bucket of water has. </rant>
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Old Oct 28, 2003, 11:50 AM   #14
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Why is something like the "NUCLEARGULAMAN PROJECT" mixed into a photographic forum or am I off topic for asking?
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