Why are Stars Not Visible in Astronaut Photos?

In summary, the reason why stars are not visible in pictures of the ISS or astronauts in outer space is due to the dynamic range of the cameras used. The brightness of the objects being photographed needs to be adjusted in order to properly expose the image, and stars are not bright enough to register in the photograph. This same issue has been questioned in regards to photos from the Moon landings. While some may question the authenticity of space photos, the most likely explanation is the dynamic range of the cameras. As for whether astronauts can see stars when looking away from bright objects in space, it is possible for their eyes to adjust and see stars, but the level of brightness and time spent in the dark would affect their ability to see them.
  • #1
Farquezy
12
0
Ive noticed every time i see a picture of the ISS or astronauts working in outer space there is NEVER any visible stars?
Why is this?
i been told that they filter it somehow since they stars would be so bright, or is there another reason

this has been on my mind for a long time
 
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  • #2
Dynamic range. Simple. When you see a suited astronaut or the ISS or a module being added, they are VERY bright. To image them with proper exposure, the brightness needs to be attenuated, and stars just aren't bright enough to register. This same question has been posed about shots from Moon landings, during the film-era. The answer is still the same.
 
  • #3
You don't see stars in pictures of sunlit objects in space for the same reason you don't see stars in pictures taken with a flash at night on earth*: the stars are far too dim to show up in the pictures.

The stars are only moderately brighter to a viewer in space than they are to a viewer on earth.

*Caveat: Most digital cameras today have a "night portrait" mode that allows you to shoot a dim background and a flash-lit foreground object at night. It does this by taking two pictures: one short exposure with the flash, then a longer exposure one without it or by taking one long exposure picture and triggering the flash part-way through: http://photography.about.com/od/camerabasics/ss/camerapresets_5.htm
 
  • #4
oh why didnt i think of that!
thank you very much
now that's cleared up
 
  • #5
There's a non-zero probability that it means that 1) all space photos are faked and 2) the people doing the faking forgot to put in the stars.

This is a good place to use Occam's razor. It's the dynamic range.
 
  • #6
Antiphon said:
There's a non-zero probability that it means that 1) all space photos are faked and 2) the people doing the faking forgot to put in the stars.

This is a good place to use Occam's razor. It's the dynamic range.
i didnt even imply any of those
thats just ridiculous to think that
 
  • #7
The human retina has a much wider dynamic range than both digital and film cameras, so I want to know whether astronauts standing on the sunlit side of the moon, or in the ISS can see stars when they look up and away from the sun. Or is it a bit like looking up from a large sports stadium on Earth when all the powerful lights are turned on - everything around the astronaut is so bright that their eyes don't become sufficiently 'night adapted' to see any but the brightest stars and planets - Sirius and Jupiter maybe. Are there reports on this?
 
  • #8
aedfrith said:
The human retina has a much wider dynamic range than both digital and film cameras, so I want to know whether astronauts standing on the sunlit side of the moon, or in the ISS can see stars when they look up and away from the sun. Or is it a bit like looking up from a large sports stadium on Earth when all the powerful lights are turned on - everything around the astronaut is so bright that their eyes don't become sufficiently 'night adapted' to see any but the brightest stars and planets - Sirius and Jupiter maybe. Are there reports on this?
That's a really good question! I'd like to know the answer to that.
 
  • #9
I don't know if there are any reports on that, but if an astronaut is looking away from everything around them that is bright then there is nothing around them reflecting light into their eyes and their eyes would adjust to the darkness, so I see no reason why they wouldn't be able to see stars. Some adjustment happens quickly, but much of our eyes' ability to adjust to changing light conditions takes several minutes.

When I do astrophotography from my deck, I may keep the inside of my house at normal lighting levels. I can walk outside and still see stars, but not as well as if I walk outside and stay there for 10 minutes. My sky isn't all that dark though, so the difference isn't all that pronounced.
 
  • #10
russ_watters said:
I don't know if there are any reports on that, but if an astronaut is looking away from everything around them that is bright then there is nothing around them reflecting light into their eyes and their eyes would adjust to the darkness, so I see no reason why they wouldn't be able to see stars. Some adjustment happens quickly, but much of our eyes' ability to adjust to changing light conditions takes several minutes.

When I do astrophotography from my deck, I may keep the inside of my house at normal lighting levels. I can walk outside and still see stars, but not as well as if I walk outside and stay there for 10 minutes. My sky isn't all that dark though, so the difference isn't all that pronounced.

Of course, the difference between a room at normal lighting levels and direct sunlight is a difference between 50 lux and 32,000-130,000 lux.
 
  • #11
As long as you aren't in the direct sun light, you should be able to see stars. It seems to me like having a light shined at your back whilst you are looking at the stars.
 

Related to Why are Stars Not Visible in Astronaut Photos?

1. Why are stars not visible in astronaut photos?

Stars are not visible in astronaut photos because of the way cameras capture light. Cameras used in space photography are designed to capture bright objects, such as planets and stars, and dim objects, such as planets and galaxies, in separate exposures. This is because the bright light of the stars can cause the dimmer objects to be overexposed and not visible in the photo.

2. Can astronauts see stars in space?

Yes, astronauts can see stars in space. In fact, the view of the stars from space is unobstructed by the Earth's atmosphere and can be even more spectacular. However, in order to capture these stars in a photograph, astronauts need to use a special camera and adjust the settings properly to avoid overexposure.

3. Are stars not visible in astronaut photos a conspiracy?

No, the absence of stars in astronaut photos is not a conspiracy. It is simply a result of the limitations of the cameras used in space photography. NASA has explained this phenomenon and has even released photos taken by astronauts that do show stars in the background.

4. Can astronauts take photos of stars from space?

Yes, astronauts can take photos of stars from space. They have access to special cameras and techniques that allow them to capture the beauty of stars in space. However, as mentioned before, this requires adjusting the camera settings and using specific techniques to avoid overexposure.

5. Are stars not visible in astronaut photos a recent discovery?

No, this has been known for a long time. The first photos taken by astronauts in space in the 1960s also did not have any stars visible. This is due to the same reasons mentioned earlier - the camera settings and exposure limitations. However, as technology has advanced, we now have more photos of stars in space captured by astronauts.

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