Strange variable daylight brightness within Prepar3D v2.4

[OleBoy]

I've been doing a lot of repainting lately. Popping in and out of the simulator, going around aircraft to look at them for anomalies. Here's the scenario.

Prepar3D 2.4 loads and the plane is in front of me. It's a sunny day with scattered clouds in the sky. No clouds on the plane I'm viewing. As I go round the plane in a 360 degree circle (while looking at the aircraft) the light goes from bright to dim. Like on a dimmer switch connected to a light in your house. Depending on which direction the nose is pointed, the area where the brightness changes, varies. So this is not being caused by by the (alpha/spec) paint scheme or a specific aircraft.

I went into the weather settings and changed it to clear skies as a test. When the sim reloaded I did the same 360 walk around it. The symptom of blinking daylight was gone.

I'm wondering if anyone else experiences this.

Edit:
The problem may be my video card getting overloaded. I forgot I'd edited the cloud draw distance from 8 to 12. That tosses a lot of clouds out there. Back to the original setting it went.

[Daube]

Usually, when the day light changes, that's because some cloud is masking the sun. Since the clouds are moving, the brightness of the environment around you comes and goes.
Also, the HDR effect plays a little role here as well. This effect tries to simulate the fact that your eyes eventually get used to the brightness, by reducing it after a few seconds
So, if you look at a dark virtual cockpit, and then you raise your view to look outside, then everything will be so bright.... but if you wait a few seconds, this brightness level will go down. And then, if you look again at the VC, it will be so dark, for the very same reason.

However, since you said the phenomenom was gone after you switched to clear skies, I thing the part of my explanation above applies. I don't think your video card was overloaded.

[Dimus]

I also see that and attribute it to the clouds masking the sun. I kinda like it actually.

[roger-wilco-66]

Also, when the sun is low like before dawn or after sunset, the lighting changes rapidly. You actually can see the shadows move on the ground.

[OleBoy]

My thinking it was my video card was wrong. I didn't even consider that every time I load the plane I'm painting, I load the same "saved" flight every time. Same time of day, weather, sun angle, clouds and parking spot. Then I select the model. DOH! Shazam, a Gomer Pyle simulation

Thanks everyone