Celestia Forums

I've notice that an object placed as far out as Pluto seems to be as brightly lit as an object that is placed as close as Venus.
Is this just the way it works in Celestia? or is there a setting I do not have turned on or am I just crazy?

From my experience, objects great distances from their star are still illuminated as much as an object close to the star. Of course, when you're far from it, the planet is drawn by a little white (usually white at least) dot. This dot appears dimmer for objects that are farther from their stars then it would if the same object was close to the star.

I put 2M1207 b in Celestia once and due to it's great distance from the host star, the white dot was never visible (I usually have the maximum visible magnitude set to 9 or 10). If I wanted to see the planet, I had to get close enough to where it was a planet, not a dot.

(That's probably a horrifically butchered way to explain it )

Reiko,

This is not a bug in Celestia or with your setup. It is a deliberate feature.

There are two reasons for displaying Pluto as brightly as Venus:

1) Were you actually out in space viewing Venus, your pupils would constrict to allow less light in. While, if you where viewing Pluto, your pupils would open up and allow more light in. The net effect would be that you would see both objects with approximately the same amount of detail.

It is like seeing objects indoors and then walking out into a brightly lit day: At first everything is blindingly bright, but soon your eyes adjust and you see the grass and trees that are reflecting many times more light than the indoor objects were just as easily as you saw the objects indoors.

Similarly, when you step back in, your eyes adjust and what, at first, seems like a dark room, becomes a normally lit area.

Think of Celestia as doing that eye-adjusting automatically and instantly.

2) Your monitor simply can't handle the incredible range it would take. If it could then Celestia would have to distributed with a warning not to look at images of the sun from closer than orbit of Jupiter, and people would be asking for a flashlight function so they could see stuff on Pluto.

As it so happens, I am developing a version of Celestia that can simulate very bright light and adaptive exposure values - more commonly known as hdr (high dynamic range) imagery.

For regular progress updates and screenshots, watch the forum thread titled "Advanced lighting".

Reiko wrote:I've notice that an object placed as far out as Pluto seems to be as brightly lit as an object that is placed as close as Venus.
Is this just the way it works in Celestia? or is there a setting I do not have turned on or am I just crazy?

...crazy