Archived posting to the Leica Users Group, 2011/01/28

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Subject: [Leica] An unusual visual phenomenon
From: sonc.hegr at gmail.com (Sonny Carter)
Date: Fri, 28 Jan 2011 09:20:16 -0600
References: <AANLkTiktcTv-zGMt28scRocnMzhkKwscDxX8vRBpOL=7@mail.gmail.com>

Other than the possible fact that the envelopes might actually reflect
whiter than the snow . . . Sunlight is rather blue in the spectrum.  (When I
was working in film production, making commercials, those little nuances
could really take you for a ride.)

In the house, you don't have that direct comparison,  the light sources will
be mixed, so your brain will give you a white envelope, just like you want
it to be.


On Fri, Jan 28, 2011 at 8:56 AM, Lawrence Zeitlin <lrzeitlin at 
gmail.com>wrote:

> Yesterday afternoon, when shoveling our recent 15" snowfall off the
> driveway, I paused at the mailbox to get the day's mail. I set the letters
> down on the snowbank to close the box when I noticed that all the white
> envelopes appeared a pale shade of blue. When I took them in the house they
> appeared normally white. While I have no definitive explanation for the
> "blue" envelopes, I have written before that the eye, mediated by the
> brain,
> does not see reality but sees what it expects to see. We alter the visual
> scene until it conforms to our expectations. Colors are viewed in their
> "proper" hues despite ambient illumination, shapes are altered, sizes
> changed to offset their diminishment by perspective, and so on. Reality is
> in our mind, not in the objective scene.
>
> All I can suggest is that after a couple of hours of shoveling I expected
> the snow to be white despite the fact that it was yellow tinged because of
> the late afternoon sun. By shifting the color balance of the scene to meet
> my expectations, perhaps the truly white envelopes were shifted into the
> blue. Does anyone have an explanation?
>
> Larry Z
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information
>



-- 
Regards,

Sonny
http://sonc.com/look/
Natchitoches, Louisiana

USA


In reply to: Message from lrzeitlin at gmail.com (Lawrence Zeitlin) ([Leica] An unusual visual phenomenon)