 |
|
|
|
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Among other things, Warp wrote:
> Jellby <jel### [at] m-yahoo com> wrote:
>> In outer space this doesn't happen and it
>> should be possible to see the stars you cover the sun (and other bright
>> bodies), but I've never been there to try.
>
> As I said, it's perfectly possible to photograph stars in space. You
> just need to set the exposure time of the photographing device so long
> that it captures the light of the stars.
> [...]
Yes, I agree. I was just pointing out that, under the atmosphere, it's not
just a matter of exposure time.
--
light_source{9+9*x,1}camera{orthographic look_at(1-y)/4angle 30location
9/4-z*4}light_source{-9*z,1}union{box{.9-z.1+x clipped_by{plane{2+y-4*x
0}}}box{z-y-.1.1+z}box{-.1.1+x}box{.1z-.1}pigment{rgb<.8.2,1>}}//Jellby
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
In article <3ea1aab9@news.povray.org>, Warp <war### [at] tagpovrayorg>
wrote:
> Space movies are always unrealistic in this matter. There planets and
> stars are perfectly visible all alike, which can't be achieved with any
> ordinary photographing device. (In theory you would need some kind of
> digital device which analyzes the image and corrects the exposure in
> different parts of the image depending on their brightness.)
Well, they would be an unrealistic representation of what you would get
from a present-day video camera, that doesn't make them unrealistic.
If I were designing a video camera for use in this kind of environment,
I'd use multiple cameras with different settings and composite them
together, or try to find a sensor with sufficient dynamic range. It
could be as simple as a thin layer on the CCD that changes local opacity
depending on the brightness of light on it. It could be passive, like
today's color changing sunglasses, or an active liquid crystal filter.
Or you could make a filter that varies in opacity evenly over the entire
filter, and just take consecutive frames at different opacity levels,
processing them together into the final image as you would with multiple
cameras.
--
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Christopher James Huff <cja### [at] earthlinknet> wrote:
> If I were designing a video camera for use in this kind of environment,
> I'd use multiple cameras with different settings and composite them
> together, or try to find a sensor with sufficient dynamic range. It
> could be as simple as a thin layer on the CCD that changes local opacity
> depending on the brightness of light on it. It could be passive, like
> today's color changing sunglasses, or an active liquid crystal filter.
> Or you could make a filter that varies in opacity evenly over the entire
> filter, and just take consecutive frames at different opacity levels,
> processing them together into the final image as you would with multiple
> cameras.
All this to simply get some white dots on the image?-)
Space movies often exaggerate the beautiness of stars in space, but
I wouldn't be surprised if actually they were just extremely boring
white dots... :)
The images of the Hubble telescope are marvelously beautiful... But those
images are photographind details thousands of light-years big. You don't
get that kind of colorful images when photographing a planet or a
spaceship...
But anyways, the point is making a visually pleasant artistic image,
not a physically correct one. :)
--
#macro N(D)#if(D>99)cylinder{M()#local D=div(D,104);M().5,2pigment{rgb M()}}
N(D)#end#end#macro M()<mod(D,13)-6mod(div(D,13)8)-3,10>#end blob{
N(11117333955)N(4254934330)N(3900569407)N(7382340)N(3358)N(970)}// - Warp -
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Warp wrote:
> I wouldn't be surprised if actually they were just extremely boring
> white dots... :)
Hundreds of years in the future, makind will send out a space probe
that will discover that the universe is, in fact, just a massive
spherical computer display surrounding the solar system.
--
Tim Cook
http://home.bellsouth.net/p/PWP-empyrean
-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GFA dpu- s: a?-- C++(++++) U P? L E--- W++(+++)>$
N++ o? K- w(+) O? M-(--) V? PS+(+++) PE(--) Y(--)
PGP-(--) t* 5++>+++++ X+ R* tv+ b++(+++) DI
D++(---) G(++) e*>++ h+ !r--- !y--
------END GEEK CODE BLOCK------
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
In article <3ea3055e@news.povray.org>, Warp <war### [at] tagpovrayorg>
wrote:
> All this to simply get some white dots on the image?-)
Nah, so people won't ask where the stars are. ;-)
Really, having a visual background of some sort would be useful, just
for ease of mind, or for judging changes in orientation on the fly
(assuming you would ever need to do so). You could have the computer
project a background grid, but why not just make something that is
already there visible? Also, the idea is to mimic what the eye would
see, and it can adapt so the stars are visible. You can see the stars
when standing on the sunlit side of the moon, it's just hard to catch
them on film. And you'll probably have these types of sensors anyway,
they would be lighter than multiple cameras.
> Space movies often exaggerate the beautiness of stars in space, but
> I wouldn't be surprised if actually they were just extremely boring
> white dots... :)
Are you saying the astronauts we've sent up are exaggerating too?
> The images of the Hubble telescope are marvelously beautiful... But those
> images are photographind details thousands of light-years big. You don't
> get that kind of colorful images when photographing a planet or a
> spaceship...
And they're nothing like what this camera would show. They are not what
it is intended to show. Having a ship go through a densely foggy nebula
is unrealistic, showing stars is not.
--
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Christopher James Huff <cja### [at] earthlinknet> wrote:
> You can see the stars
> when standing on the sunlit side of the moon
I don't think you can see many stars.
Even here on Earth, if you are in a brightly lit room your eyes are
adapted to the brightness (the size of the pupils and all that stuff)
and it's difficult to see many stars outside, even if it's a dark and
clear night. You need to turn off all lights and wait until your eyes
adapt to the darkness before you begin seeing lots of stars.
--
plane{-x+y,-1pigment{bozo color_map{[0rgb x][1rgb x+y]}turbulence 1}}
sphere{0,2pigment{rgbt 1}interior{media{emission 1density{spherical
density_map{[0rgb 0][.5rgb<1,.5>][1rgb 1]}turbulence.9}}}scale
<1,1,3>hollow}text{ttf"timrom""Warp".1,0translate<-1,-.1,2>}// - Warp -
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
In article <3ea40516@news.povray.org>, Warp <war### [at] tagpovrayorg>
wrote:
> Even here on Earth, if you are in a brightly lit room your eyes are
> adapted to the brightness (the size of the pupils and all that stuff)
> and it's difficult to see many stars outside, even if it's a dark and
> clear night. You need to turn off all lights and wait until your eyes
> adapt to the darkness before you begin seeing lots of stars.
In that case, the brightness is on your side of the glass, so glare
masks many of them. Open the window and you can see more stars. Also,
your eyes move around, adapting to what they are looking at, and have a
wider dynamic range than most cameras. Just immediately after opening a
door and walking out of a brightly lit room, I can see many stars, and
on the Moon there isn't an atmosphere to absorb and scatter so much
light. From what I've read, the stars are quite brilliant when viewed
from the Moon.
--
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Christopher James Huff <cja### [at] earthlinknet> wrote:
> In that case, the brightness is on your side of the glass, so glare
> masks many of them.
Glass has nothing to do with it.
--
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
In article <3ea44b2d@news.povray.org>, Warp <war### [at] tagpovrayorg>
wrote:
> > In that case, the brightness is on your side of the glass, so glare
> > masks many of them.
>
> Glass has nothing to do with it.
When you are in a brightly lit room looking out the window (as you gave
in your example), the glass is very important. The reflection of the
interior of the room is far brighter than many stars, and covers a much
wider area. The helmet visor doesn't have a brighter interior to
reflect, which is why I gave the example of opening a door and glancing
out. Try it: the stars are visible. From what I've read about what the
astronauts actually saw, at least when you are facing upward and away
from the sun, the stars are perfectly visible.
--
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Christopher James Huff <cja### [at] earthlinknet> wrote:
> When you are in a brightly lit room looking out the window (as you gave
> in your example), the glass is very important.
Forget the glass. Remove it. Look out the door. Whatever.
> which is why I gave the example of opening a door and glancing
> out. Try it: the stars are visible. From what I've read about what the
> astronauts actually saw, at least when you are facing upward and away
> from the sun, the stars are perfectly visible.
Do you know the reason why your pupils get larger and smaller depending
on the amount of light?
When the pupils get smaller, less light gets through and thus you don't
see dimmer light.
This is the reason stargazers (those using telescopes) never use white
flaslights but red ones. It takes lots of time for the eyes to adapt to
the darkness.
You may see *some* stars, the brightest ones, but only a minimal percent.
--
#macro N(D)#if(D>99)cylinder{M()#local D=div(D,104);M().5,2pigment{rgb M()}}
N(D)#end#end#macro M()<mod(D,13)-6mod(div(D,13)8)-3,10>#end blob{
N(11117333955)N(4254934330)N(3900569407)N(7382340)N(3358)N(970)}// - Warp -
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
|
|
