A nice debunking of the old "No Stars" meme

[Zakalwe]

Of course, the hoaxies would handwave this away. Nevertheless, it's a nice demonstration of the type of exposures needed to capture stars.

http://www.physicsinsights.org/apollo-stars-1.html

[Ishkabibble]

Awesome site!

[darren r]

I didn't know that about the magnetic field not blocking X-rays and UV from the Sun. I guess that means it's impossible to take pictures on Earth too.

[Zakalwe]

I didn't know that about the magnetic field not blocking X-rays and UV from the Sun. I guess that means it's impossible to take pictures on Earth too.

Our atmosphere shields us from the majority of UV light (virtually all UV-C, about 96% of UV-B) and just about all X-Rays.

[Dalhousie]

For what it's worth a few years ago I was in charge of a drilling project with a night shift.  We were drilling on a dry lake bed composed of grey clay, very lunar in the dark.  The light was strongly floodlit of course although not quite to daylight standard, certainly good enough to read and work by.  Here are some photos with my Fuji S point and shoot camera.  Because of file size restrictions I will show the photos in the next three posts. 

[Dalhousie]

The first photo shows the floodlight arrangement.  There are two sets of floodlights about 90 degrees apart. Because of the saturation of the photo from the lights, the illuminated area is much brighter than it seems. This is a clear moonless night out in the desert, well away from any.  The nearest town with a population of about 1000 people (Menindee) was about 15 km away.  The next photo is taken just to the left of the left hand floodlight tower.

[Dalhousie]

The second photo is a view looking west, showing how much brighter the area looks when not looking at the floodlights.  The bases of the floodlight mounts can be seen on the left hand side. The ground is brightly lit, though not quite to terrestrial daylight standards, let alone lunar ones.  Note there are no stars visible, despite being a very starry night.

[Dalhousie]

The third was taken seconds before, and is due east.  The orange blob is the rising Moon, several days after full.  A few house lights are also visible on the opposite lake shore (six or seven km distant).  You can see that the foreground is quite well lit to a distance of several hundred metres from where I am standing.  This is still enough to render the stars invisible.  Note double shadows from the two sets of lights.  And yes, I did take these photos to illustrate the risibility of the no stars claim.

[ka9q]

The other thing to note is the small size of the floodlit area, as compared to many km² of evenly and brightly lit lunar landscape. I don't think anyone has ever figured out how to reproduce that kind of lighting on a set, which is why there's such a stark difference between Apollo images and every movie set on the moon, including 2001.

[JayUtah]

The other thing to note is the small size of the floodlit area, as compared to many km² of evenly and brightly lit lunar landscape. I don't think anyone has ever figured out how to reproduce that kind of lighting on a set, which is why there's such a stark difference between Apollo images and every movie set on the moon, including 2001.

Indeed, witness our deliberate attempt to create a lunar set.  You have to choose between directional light or a "wash" that lights the whole terrain.  You can't have both without a nearby sun.

http://www.clavius.org/bibzz1.html

[ka9q]

Indeed, witness our deliberate attempt to create a lunar set.  You have to choose between directional light or a "wash" that lights the whole terrain.  You can't have both without a nearby sun.

I think you mean a distant sun, so the incoming light is nearly collimated. And it has to come from a half-degree source so shadows will have exactly the right degree of sharpness.

[Glom]

The third was taken seconds before, and is due east.  The orange blob is the rising Moon, several days after full.  A few house lights are also visible on the opposite lake shore (six or seven km distant).  You can see that the foreground is quite well lit to a distance of several hundred metres from where I am standing.  This is still enough to render the stars invisible.  Note double shadows from the two sets of lights.  And yes, I did take these photos to illustrate the risibility of the no stars claim.

Nice fake moonlanding set you got there.

Indeed, witness our deliberate attempt to create a lunar set.  You have to choose between directional light or a "wash" that lights the whole terrain.  You can't have both without a nearby sun.

I think you mean a distant sun, so the incoming light is nearly collimated. And it has to come from a half-degree source so shadows will have exactly the right degree of sharpness.

What about using spherical reflectors to light the surface indirectly like they do in flight simulators? Could that work?

[ka9q]

What about using spherical reflectors to light the surface indirectly like they do in flight simulators? Could that work?

Not sure how that would work.

You need to uniformly light a very large area (tens of km²) with a single light source. The light source must be almost perfectly collimated over this entire area, meaning that the incoming light rays follow near parallel lines and all the shadows will be parallel (in space, not necessarily how they appear on film). But the rays can't be too parallel, i.e., a point source, as that would generate shadows that are too sharp. The light must be uniformly spread over a 0.5 degree disc with a very sharp edge.

Oh, and the light source has to slowly climb in elevation and possibly move in azimuth as well, depending on the supposed lunar location.

[smartcooky]

What about using spherical reflectors to light the surface indirectly like they do in flight simulators? Could that work?

Not sure how that would work.

You need to uniformly light a very large area (tens of km²) with a single light source. The light source must be almost perfectly collimated over this entire area, meaning that the incoming light rays follow near parallel lines and all the shadows will be parallel (in space, not necessarily how they appear on film). But the rays can't be too parallel, i.e., a point source, as that would generate shadows that are too sharp. The light must be uniformly spread over a 0.5 degree disc with a very sharp edge.

Oh, and the light source has to slowly climb in elevation and possibly move in azimuth as well, depending on the supposed lunar location.

Oh that's easy.

You just need to position an immensely powerful light source of a few gazillion terawatts, about 93 million miles away.

 I reckon you could light up one whole side of the moon with that sucker.......Oh, hang on.

[ka9q]

You just need to position an immensely powerful light source of a few gazillion terawatts, about 93 million miles away.

385 yottawatts (YW), to be exact. That's a lotta watts.