An astronaut looking out the window of the space station will see just as much direct sunlight, if not more, than I will looking out my apartment window on a cloudless day. If I want to take a picture out my sunny window, I'll naturally use a fast exposure and a narrow aperture setting on my camera, which lets only a short burst of light in — a little like the way the pupils of the eye contract in sunlight, so the bright light isn't so painful.
Naturally, the astronauts or satellites in space are going to do the same thing when taking pictures of sunlit objects, since it's just as bright up there. Fast exposure times means they can get good pictures of the bright Earth or lunar surface, but it also means no stars in the picture.
Even in space, stars are relatively dim, and simply don't produce enough light to show up in photos set for bright sunlight. How many stars do you see? And what happens if you try to take a picture of something in the foreground, do you still see the stars behind? And even if the stars are often not visible in all photos, videos, and live streams, there are plenty of beautifully shot images showing the stars, and even the Milky Way , photographed from the ISS that are available to stare at to your heart's content.
The bright dot among the stars is the planet Venus. This website uses cookies to improve user experience. By continuing to use our website you consent to all cookies in accordance with our cookie policy. Share on Facebook. Longer exposures collect more light -- helping to detect fainter things -- than shorter exposures.
There's no real equivalent for exposure setting in human vision -- we notice more when we stare at something longer, but that's not quite the same thing. Photographs of the night sky that are full of stars are long exposures, often taking many minutes -- it takes that long for the camera to detect enough photons for a pretty view. Short exposures don't catch stars.
The photo below was a minutes-long exposure. What looks like sunlight on the mountains is actually moonlight. The Apollo astronauts' photos were exposed for the brightly sunlit lunar surface and white space suits. These exposures were too short to detect stars in the sky. Space cameras can permit a very wide range of exposure settings. They used the shortest exposure setting when they were flying past Jupiter, which is much closer to the Sun and much brighter than Pluto.
They use the longest exposures for the faintest targets -- distant worlds in the Kuiper belt. As an aside, this answers another common question we get about space images: how can cameras see to take pictures so far from the Sun, where the light is so comparatively dim?
The answer: we send sensitive cameras and, if necessary, take long exposures. Voyager 2 at Neptune provides good examples of what happens when we send a camera that's not sensitive enough. Designed for Jupiter and Saturn, it had a tough time seeing in the relative dark at Neptune. Is your camera capable of seeing both dimly-lit and well-lit things in the same image? Or does its light-collecting capacity get quickly overwhelmed by brighter things before it's had time to detect any light from dimmer things?
Here is where our eyes generally do much better than our cameras. When I see a friend sitting in front of a window, I can see their face just fine because my eyes are capable of discerning detail in both shadow and sunlight. Then I take out my camera and take a picture, and it looks terrible. But wait -- modern digital cameras have a trick that mimics what the human eye and brain do.
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