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3 Nov 2024 01:08:51 EDT (-0400)
  projecting an image through glass [~31KB Jpg] (Message 1 to 7 of 7)  
From: Bob Hughes
Subject: projecting an image through glass [~31KB Jpg]
Date: 18 Aug 2000 07:16:35
Message: <399d1b13@news.povray.org>
I was trying to see how refraction + photons and all that would work out for
projecting images from a light.
Apparently no refraction actually gets used since the image is the same with
or without the glass lens.  Only that photons show up, of course, in the
media air.
Just figured I'd post an image of it while talking about it.  So, I guess
it's a moot thing to try and do image projection in this manner.

Bob
--
omniVerse http://users.aol.com/persistenceofv/all.htm


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From: Christoph Hormann
Subject: Re: projecting an image through glass [~31KB Jpg]
Date: 18 Aug 2000 08:22:42
Message: <399D2AB3.ABDB714E@schunter.etc.tu-bs.de>
Bob Hughes wrote:
> 
> Apparently no refraction actually gets used since the image is the same with
> or without the glass lens.  Only that photons show up, of course, in the
> media air.

A projector, that works just fine without a lens - you should invent such a
thing for real life :-)

I wonder how sharp the text appears in the media, normally you would expect all
structures to appear in a conic shape expanding from the light source.  

Christoph

--
Christoph Hormann <chr### [at] gmxde>
Homepage: http://www.schunter.etc.tu-bs.de/~chris/


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From: ryan constantine
Subject: Re: projecting an image through glass [~31KB Jpg]
Date: 18 Aug 2000 16:49:28
Message: <399DA14A.C6BC0F3B@yahoo.com>
what if you use a cylindrical spotlight with parallel light rays.  the
reason is that in a projector, the bulb is so big in relation to the
film that i'm pretty sure it acts like parallel rays and not a point
source.

Bob Hughes wrote:
> 
> I was trying to see how refraction + photons and all that would work out for
> projecting images from a light.
> Apparently no refraction actually gets used since the image is the same with
> or without the glass lens.  Only that photons show up, of course, in the
> media air.
> Just figured I'd post an image of it while talking about it.  So, I guess
> it's a moot thing to try and do image projection in this manner.
> 
> Bob
> --
> omniVerse http://users.aol.com/persistenceofv/all.htm
> 
>  [Image]


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From: Bob Hughes
Subject: Re: projecting an image through glass [~31KB Jpg]
Date: 18 Aug 2000 17:29:05
Message: <399daaa1@news.povray.org>
"ryan constantine" <rco### [at] yahoocom> wrote in message
news:399DA14A.C6BC0F3B@yahoo.com...
| what if you use a cylindrical spotlight with parallel light rays.  the
| reason is that in a projector, the bulb is so big in relation to the
| film that i'm pretty sure it acts like parallel rays and not a point
| source.

Good idea, I think you're probably right.  Just wouldn't work at all for
this then since the glass doesn't affect it at all unfortunately.  Would be
a great thing if POV-Ray could also do optics simulation.

Bob


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From: Sander
Subject: Re: projecting an image through glass [~31KB Jpg]
Date: 18 Aug 2000 19:04:21
Message: <MPG.1407d225cbe0ec20989686@news.povray.org>
In article <399d1b13@news.povray.org>, 
per### [at] aolcom?subject=PoV-News says...
> I was trying to see how refraction + photons and all that would work out for
> projecting images from a light.

Not that I understand the subject of this post, Bob, but why are the 
enclosed spaces in the several characters white?
-- 
Regards,  Sander


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From: Bob Hughes
Subject: Re: projecting an image through glass [~31KB Jpg]
Date: 19 Aug 2000 06:09:58
Message: <399e5cf6@news.povray.org>
"Sander" <san### [at] stolscom> wrote in message
news:MPG.1407d225cbe0ec20989686@news.povray.org...
|
| Not that I understand the subject of this post, Bob, but why are the
| enclosed spaces in the several characters white?

Because of a quick test image for trying this with.  I should have put the
gradient fill down first, the text went in first.  Thought that would be
fine though, until I saw the white with filter 1 made it clear, hadn't
thought of that.  Only reason it turns white again is because it's shown on
a white wall.
Understanding the subject is easy.  All I was trying to do is see how
refraction through glass would effect the light shining into it.  The
photons show it refracting in the media, but near as I can tell there isn't
any change of the actual light source rays  :-(
This leads me to believe that were I to somehow turn off the image map
itself yet leave the photons there would be a refracted projection there.
For instance, removing the white wall and shine it into media air alone.

Bob


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From: Chris Huff
Subject: Re: projecting an image through glass [~31KB Jpg]
Date: 21 Aug 2000 22:39:14
Message: <chrishuff-7F20C1.21403521082000@news.povray.org>
In article <399e5cf6@news.povray.org>, "Bob Hughes" 
<per### [at] aolcom?subject=PoV-News:> wrote:

> Understanding the subject is easy.  All I was trying to do is see how 
> refraction through glass would effect the light shining into it.  The 
> photons show it refracting in the media, but near as I can tell there 
> isn't any change of the actual light source rays  :-(

Maybe if you reflected the beam off a mirror before going through the 
image and lens...or maybe not. Hmm.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><


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