On Mon, 14 Dec 2015 20:00:37 +0000 (UTC) jim bell <jdb10987@yahoo.com> wrote:
But if you open up the aperture (a variable-diameter shutter designed to allow more, or less, area for light to come in and expose the film), and perhaps if you increased the shutter-speed from, say, 1/1000 second to maybe 10 seconds (and putting the camera on a tripod to ensure it doesn't move), THEN you will be able to photograph stars.
Truth is I used to take pictures and print/develop them...a long time ago (I still have some b/w paper lying around). I partially overlooked the exposure time issue because I was assuming that the fact that the moon has no atmosphere somehow made a substantial difference. Anyway, the moon pictures that had people or landscapes in them can't show the stars, but it is still possible to take pictures of the stars from the moon, with a little care. Are there any such pictures from the 60s? (then again, pictures of a starry sky wouldn't prove that there were any people on the moon...)
What about radar resolution? Is it possible to track a 5 x 5 x 5 m object from a distance of 350,000 kilometers?
That should be easy. And it would be far easier if built onto that object are some microwave-sized "corner cubes reflectors" https://en.wikipedia.org/wiki/Corner_reflector ,
Yes, interesting objects. I knew that cat's eyes have that property. So putting corner reflectors on an object makes it easier to track it, but it doesn't say anything about how easy it is in absolute terms? A search for "apollo corner reflectors radar" doesn't bring anything as far as I can see. Only references to optical reflectors on the moon.
which have the peculiar property of sending radar (or light, etc) directly back in the direction from which it came. Optical corner-cubes are easy to find: They are on the backs of cars, and are used as visual retroreflectors on roads. They are much better than Scotchlite https://en.wikipedia.org/wiki/Retroreflective_sheeting , which is made from tiny glass spheres. Jim Bell
http://petapixel.com/2015/05/26/film-vs-digital-a-comparison-of-the-advantag... "A release by Kodak showcased that most film has around 13 stops of dynamic range." That's a factor of about 8000. Jim Bell