Dust in space.
Might be possible for both a ice crystal cloud and water droplet cloud to be
side by side, and thin, with a couple very bright stars or plane lights or
whatever would work there shining through.  Not sure if there would be different
"flares" or not but it seems a likelihood to me.
So not all such things would be in the lens of a camera.  In fact I know window
screening is one thing that can cause it so maybe a square mesh one next to a
hexagonal mesh?

Bob

"Ken" <tyl### [at] pacbellnet> wrote in message
news:38C32992.601EA36B@pacbell.net...
|
| Glen Berry wrote:
| >
| > >I'd be interested to know from one of the photographers out there if you
can
| > >actually get two different shaped lense flares in the same image.
| > Yes... but it would almost certainly involve multiple exposures, and
| > in this case, moving the lighting between exposures or multiple lights
| > that are individually switchable.
| >
| > First, take one exposure with a light arranged to give you the
| > highlight on the left. Use a 6-point star filter for this exposure.
| >
| > Second, move the light to a new position to give the highlight on the
| > right. Use a 4-point star filter to photograph the same scene with the
| > new lighting. This second exposure is done on the same frame of film
| > as the first.
| >
| > Individual exposure times will need to be cut in half, in relation to
| > a normal single exposure of the scene, to restore a proper over-all
| > brightness for the frame.
| >
| > So yes, it can be done.
| >
| > Later,
| > Glen Berry
|
| I am not altogether convinced that multiple exposures are necessary. For
| example I was watching a PBS program the other day that talked about the
| formation of new stars. One thing that I noticed in the actual star images
| they were showing was that perhaps one in one thousand stars shown were
| bright enough that they had star shaped flares coming off of them. These
| were present not only in the center of the image but reaching out to the
| edges as well.
|
| --
| Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
| http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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On Sun, 05 Mar 2000 19:44:18 -0800, Ken <tyl### [at] pacbellnet> wrote:

>I am not altogether convinced that multiple exposures are necessary. For
>example I was watching a PBS program the other day that talked about the
>formation of new stars. One thing that I noticed in the actual star images
>they were showing was that perhaps one in one thousand stars shown were
>bright enough that they had star shaped flares coming off of them. These
>were present not only in the center of the image but reaching out to the
>edges as well.

To generate the effect in the rendering in question, via photography,
one will need two different star filters to achieve the effect
reliably and predictably. Of course, there is almost always another
way, but what I outlined is probably the most practical method.

One thing you curiously don't address is the idea of some stars having
a different number of "points"compared to other stars in the same
image. Did that PBS program show an image such as that? I doubt it.
Normal lens flare, star filters, and such, produce the same number of
points on each flared highlight. Not all highlights are bright enough
to exhibit the effect noticeably. Of the ones that are, you will find
that they have the same number of points.

Later,
Glen Berry

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