Rauf wrote: ↑Sat May 27, 2023 1:12 pm
Do Voyager pictures of Uranus and Neptune show these planets as bright as a human eye could see if they were close to them? Since they are so far, I think not much sunlight reaches those planets, but in famous pictures of Voyager of Neptune and Uranus, They look really bright. Are they like this because those pictures area composition of multiple pictures stacked together? Or are they enhanced in a way so we could see them more easily?
The light level at Neptune is about the same as in a well lit room, which means you could easily see it. And it wouldn't look much different to you than Earth does when you're at Earth. Because that's how our eyes and brain work. It's the same reason that an object in your hand when you're standing in sunlight looks about the same as it does when you're in your well lit living room at night, despite the ambient brightness differing by a factor of 1000 (which is the same as the difference between sunlight at Earth and at Neptune). Our eyes basically scale things so that the brightest neutral color appears white. We do the same thing with images (something Ansel Adams developed with his Zone System). Most images are processed so that the lightest pixels are scaled to white, and the darkest to black, which maximizes the dynamic range.
Of course, if we could somehow see the Earth and Neptune together, lit as they are, we'd barely see Neptune at all. (This is why we don't see stars in images of the planets.)
If you look at Neptune through a telescope (which yields exactly the same brightness as if you were much closer to it) you'll see a white (or bluish) disk. To your eye it will be bright.
Crescent Neptune and Triton
