Bright Stars!

General discussion about Celestia that doesn't fit into other forums.
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LordFerret M
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Re: Bright Stars!

Post #21by LordFerret » 01.04.2009, 05:11

That is quite possible, and quite normal. The human eye is often not perfect in optical sense. Just like a camera's lens, the human eye can have lens imperfections as well... from low order aberrations like astigmatism, to high order aberrations such as corneal scratches or vitreous filaments or retinal detachment. I myself have vitreous filaments... so damned annoying! :evil: :lol:

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Imy
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Re: Bright Stars!

Post #22by Imy » 01.04.2009, 13:49

It's interesting...

The effect depicted by Hungry4info can be also considered as an oversensitivity of the eyes like in cameras : when a pixel of the camera receive too much of light, then the neighboorhood pixels get what is over the limit of silicium electron possibility?

Is this effect illustrated a kind of diffraction from sky components themselves of the light from sun (different from blue basic color of sky)?

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LordFerret M
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Re: Bright Stars!

Post #23by LordFerret » 01.04.2009, 17:51

If I'm understanding you correctly, yes, the relationship of overstimulated pixels in a camera verses the 'processing' of light in the retina are somewhat similar. Of what you describe about overstimulation of pixels, those pixels affecting their neighbors... Of the human eye, the retina incorporates a "lateral inhibition" network (3 layers of nerve cells (rods and cones) separated by by 2 layers of synapses) which processes the incoming light, that processed data then passing on to the brain for image reconstruction. That "lateral inhibition" network behavior is similar in effect to what happens in the overstimulation of the pixels in a camera. What I find more interesting however, is the manner in which the brain reconstructs that image data. We're provided with vision quality like a HDR (High Dynamic Range) camera! :D

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LordFerret M
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Re: Bright Stars!

Post #24by LordFerret » 01.04.2009, 17:57

Here is an interesting link I've found on the subject which might interest you -
http://serendip.brynmawr.edu/bb/latinhib.html

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Imy
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Re: Bright Stars!

Post #25by Imy » 02.04.2009, 07:53

Finally, it lacks different elements to simulate the unperfect (but more common) view throught eyes. I sum up them :
-Diffraction
-Over sensitive cells effect
-Lens effects

And according to your last link, more can be added...

StarSeeker
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Re: Bright Stars!

Post #26by StarSeeker » 02.04.2009, 12:07

I think if one were to view a star from an AU away there will be a hell of a lot of glare. I agree with the OP that such would be quite a nice option to add. :)

Hungry4info, I love the wording in your post. :)

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Imy
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Re: Bright Stars!

Post #27by Imy » 22.05.2009, 08:32

For those interested in an application of these bright stars and diffraction (view hardware and atmosphere diffraction), an example have been simulated in latest versions of Stellarium : just toggle atmosphere filter in this program when you're watching the Sun! This is a simulated example of Hungry4Info's last message photographs about our sun.

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Imy
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Re: Bright Stars!

Post #28by Imy » 23.05.2009, 11:22

See yourself simulated diffraction due to atmospheric gases trought this couple of shots from Stellarium, but I invite you to see dynamical transition between atmospheric and non-atmospheric view with this stellar observation program.
These views are very instructive : they show how atmospheres appear to be a mask over all space stuffs, a streching one, and something that divises you from a surface world and a space world.
It's an illustration how space world could be seen diffrently from orbit and surface, no?
I wonder if Celestia should display this atmospheric diffraction for all bodies in space with such gaseous enveloppe like titan... But If the Sun shape is stretched by air, how should appear the big Saturn from Titan's surface?

duds26
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Re: Bright Stars!

Post #29by duds26 » 23.05.2009, 13:23

First celestia needs HDR rendering in order to simulate the differences in brightness good.
(Needs the range for calculating the over stimulation and other stuff.)
It also needs atmospheric scattering.
Then there can be talked about simulating lens effects and over stimulation and such.


And one page of posts to come to the conclusion that an eye is a little bit like a camera is a little too much.
Our eyes have lenses too, just common knowledge.
That means that artefacts caused by lenses appear in camera's and our eyes.
Last edited by duds26 on 26.05.2009, 11:27, edited 1 time in total.

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Imy
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Re: Bright Stars!

Post #30by Imy » 25.05.2009, 06:41

I'm waiting for HDR rendering so!


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