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ZEISS. Discover the fascinating world of birds, and win a birding trip to Columbia

Bino Thoughts #6 (1 Viewer)

WJC

Well-known member
Bino Thoughts 6

MORE ON THE VALUE OF THINKING A LITTLE DEEPER

As I was finishing Bino Thoughts #5, I was running out of day. I have two important examples to support the same concept. The first clearly demonstrates that we often supplant scientific evidence with our own erroneous opinions because of our level of thinking and resistance to opposing realities.

BF Illustration 1 was used on page 74 of my first binocular book. It was one of several illustrations created at MIT by neuroscientist and professor of Vision Science, Edward H. Adelson. Although the two leaves appear (to most people) to be greatly different in hue. In fact, they are EXACTLY the same. This can be proven, to those open to doubting what they THINK they know, by placing a couple of fingers just outside the apex of each.

I think BF Illusion 2 is even better. Not only is it stark, with fewer extraneous stimuli, visiting MIT’s optical illusion site one can see the two identical spheres revolving from one side to the other ... several times.

Probably the best—certainly the most frustrating for me—is BF Illustration 3, wherein it is abundantly clear that squares A and B are VERY different ... YET THEY ARE EXACTLY THE SAME!!!!!!!!!! (Sorry, Mr. Twain; I thought all the exclamation marks were necessary.)

BF Illustration 4http://www.openculture.com/2011/08/mit_checker_shadow_illusion.html—shows how it was set up and watching the young lady take a sheet of paper and move it back and forth from one square to another with its hue seemingly changing from one shade of gray to another to match the stationary square it’s placed on.

Vision Science has a lot to tell us. But what it has told us so far has burst many bubbles for those who have such concrete opinions of what they THINK see or don’t see in a given binocular.

The second example, BF Illustration 5, illustrates that those who claim to see axially and peripherally in the same instant are mistaken ... and WHY. :cat:

Cheers,

Bill
 

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KC Foggin

Super Moderator
Staff member
Opus Editor
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United States
I really can't tell you why you couldn't delete it. That's not something that has ever happened to me or have we received any complaints.
 

WJC

Well-known member
I really can't tell you why you couldn't delete it. That's not something that has ever happened to me or have we received any complaints.

Thanks for trying, anyway. Normally, there are 3 places to delete a file. This time ... None.

Cheers,

Bill
 

WJC

Well-known member
Bill rules! We love Bill! Great stuff man.

Yo ... yer baldness and b-lilja. Thank you both very much. Two nice things in a row. I’m about to be hit by a train ... Right?

Bob, I haven’t seen you in a long while. Are you well? :cat:

Bill
 

Bob A (SD)

Well-known member
Bob, I haven’t seen you in a long while. Are you well? :cat:

Thanks for asking Bill. bald1 appreciates it!

Not really. Still fighting the fight with the big C. Kinda stuck at the house since early March except for medical appointments that can't be handled via telemed. Stair Lifts have been a god send. Thankfully have great neighbors that get groceries, mail, put out the trash, etc. unbidden by me.

Got whacked by a major hail storm not long ago. Roof, siding window, deck, etc. extensive damage. Working through the insurance and contractor systems but because of winter weather, repairs might not take place until spring. Just one more issue to contend with. No risk of further damage from delays thankfully.
 
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Omid

Well-known member
United States
Hi Bill,

Thanks for your post. You are pointing to a very important aspect of human vision: It is not designed to measure/respond to absolute brightness.

The human visual organ is the brain, not the eye. The brain knows that the visual attributes of the world outside are mostly constant. Whereas the brightness registered on the photo receptors of the retina change often (due to for example, the eye focusing on a near object. The accommodation reflex automatically reduces the eye pupil during near accommodation to increase depth of focus), the brain does not consider these changes as changes in the brightness of objects.

If we assume maximum pupil diameter is 8mm and minimum is 2mm, this allows an illumination control range of 16 to 1. This is far less than the actual dynamic range of the eye which is 100,000,000,000,000 to 1 (10^14 to 1 or about 46.5 f-stops). The main purpose of the pupil is controlling aberrations (to allow maximum acuity) and controlling depth of focus. It is brain that decides how bright an object is and yes, it does consider the effect of shadows.

A similiar phenomenon happens in perception of color. A fruit (e.g. an orange) appears to have same color when is placed in a shade or under direct sunlight. This is despite the fact that the spectral density of the wavelengths being reflected from it are significantly different in these two situations.


I leave it up to the reader to deduce the implications of the above biological phenomena when using his/her binoculars.

-Omid
 
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ZEISS. Discover the fascinating world of birds, and win a birding trip to Columbia
ZEISS. Discover the fascinating world of birds, and win a birding trip to Colombia
ZEISS. Discover the fascinating world of birds, and win a birding trip to Colombia
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