Celestia Forums

I just noticed something today, about the colors of the galaxies. I'm in my computer lab right now, and my students are studying the galaxies.

In Celestia 1.4.1, on Windows XP, the galaxies are turning to a beautifull light blue, while we rotate around to look at a galaxy on its side. The effect is beautifull and appears to be pretty realistic. I don't think I ever saw this on my home computer (Mac), with Celestia 1.5.0.

I suspect something isn't rendered right on the Mac. Can anyone confirm that a galaxy is turning blue on its side, with the OS X version of Celestia 1.5.0 ?

Not me...

Firstly, the transition to bluish color in the outer galaxy regime only happens for spirals, NOT for ellipticals! The latter are older and hence well known to be shifted into the more yellow-orange spectral range.
The actual color profile for spirals I took initially from a Hubble true-color photograph (of M74) as function of the distance from the center.

I seem to remember, however that I did some color adjustments towards a less spectacular blue outer region after 1.4.1, since such intensive colors CANNOT be seen with unaided eye. As we all know this forms, however, the rendering basis for Celestia.

Yet, the spiral galaxies are still bluish towards the periphery on my computers, including LCD screens, in Celestia-CVS.

Bye Fridger

ElChristou wrote:Not me...

Please, be a bit more specific. You mean you don't see any blue effect on the sides of a galaxy ? Is it just the same gray as seen from the front ?

And what about non-OS X users ?

Since there were many changes to the galaxies rendering between 1.4.1 and 1.5.0, maybe there isn't any blue shift in 1.5.0, after all. But since the blue shift is already very nice in 1.4.1, I was wondering about this feature in 1.5.0.

Selden ? Chris ?

EDIT : Thanks Fridger (cross posting...). I'm still wondering what the spiral galaxies are looking like, in 1.5.0 on Windows. Is it supposed to be blue shifted on their sides ?

Not for me... 1.4.1 on OSX

Cham,

I explicitly checked on my Core2Duo Windows notebook --both with 1.5.0pre4 and 1.5.0CVS-- that e,g, the outer parts of M74 are still bluish if viewed frontally from Earth and even more bluish when looked from the side at close distance. My LCD screen is VERY color accurate and uses a standardized color profile. The view of M 74 on my screen looks very natural.

Bye Fridger

Thanks Fridger,

then I suspect there's a problem with the OS X version. I'll check tonight, when I'll be back home, but I'm already pretty sure there isn't any blueshift in the OS X version (just the same dull gray as on the front).

Dirkpitt ?

Cham wrote:

ElChristou wrote:Not me...

Please, be a bit more specific. You mean you don't see any blue effect on the sides of a galaxy ? Is it just the same gray as seen from the front ?

Raahh... you asked anyone could confirm that a galaxy is turning blue on its side, with the OS X version of Celestia 1.5.0; my response is neat, not me! Do you really need "No, I-cannot-confirm-that-galaxies-are-turning-blue-on-their-side-on-osX-version-of-Celestia-1.5.0"??

Anyway I hope we are not again facing a problem of color profile...

Fridger, you say your monitor use a standardized color profile; which one?

I checked on my home system (Mac), and there isn't any blue shift at all, when I rotate around a spiral galaxy to see its side. I still suspect something is wrong somewhere, about the color rendering.

Can confirm blue Galactic edges on my 1.50 Pre4 installation.

The effect isn't blinding or by any means strong, but it's there.

Just FYI.

ElChristou wrote:...Anyway I hope we are not again facing a problem of color profile...

Boouhh... I fear it...