The World Beyond BetterMost > Anything Goes
Eclipse
Shuggy:
--- Quote from: Aussie Chris on August 29, 2007, 05:04:51 pm ---Um, so what is a new moon then? Isn't that also a shadow cast on the moon by the earth? Why don't we call that an eclipse too?
--- End quote ---
The dark part of a new moon is the shadow cast on the moon by the moon itself, if you like, but that might be a confusing way to describe it.
Imagine a ball brightly lit, half bright, half in shadow. When it's full, as it was on Tuesday, the sun is directly behind us, shining straight on to it in the direction we're looking, so it looks round and flat (because it's shadowless - or rather, we can't see the shadows).
(SUN) (EARTH) (MOON)
Two weeks later the moon has moved half way around the earth till we're looking at the side in shadow, but it rises about the time the sun does, so we can't see it at all. (Only if it's exactly in front of the sun we have a solar eclipse.)
(SUN) (MOON) (EARTH)
A day or two later when it's at a slight angle, we see a sliver of the bright half, and all but a sliver of the dark half. That is the new moon.
(SUN) (EARTH)
(MOON)
(There is no permanently "dark side of the moon", though the same side always faces us; when our side is dark, the other side is lit.)
Sometimes the light reflected off the earth is bright enough to reflect back off the dark part of the new moon and back to us, and we can see "the old moon in the new moon's arms".
This stuff really ought to be taught in school. It's fairly basic to understanding our place in the Universe.
Shuggy:
--- Quote from: David on August 29, 2007, 05:22:38 pm ---Boy, those are great pics Suggy! I tried to take some pictures too, but I broke my tripod last spring and I had to hold my camera in my hand when I took them. And I am very close to the city, and the lights from downtown were washing out the intensity of the moon.
What settings did you use? I used ss=4 sec., ap= F2, spot metering, noise reduction, 8x zoom (analog), OEV -2, ISO 1000.
Nice pics Suggy! :D
--- End quote ---
Thanks!
My camera is also digital but much less professional and I used the automatic setting for night photography. It seemed to take a second or two. Because of the huge dark sky, it overexposed the full moon, but got the eclipsed moon about right. I still haven't found how to measure spot exposures.
I have seen a simple formula for exposing film for the moon. Because the lit surface of the moon is always the same brightness (except during an eclipse) it was something like 1/filmspeed at a particular aperture, or the equivalent at other apertures (ie if one goes up one step, the other goes down one). But when I Goggled it, it proves to be more comlicated.
Katie77:
Fantastic pics Shuggy.....
I stood out on my balcony and watched it over here in Australia as well....it was amazing....
Ellemeno:
I thought some people might not know that Shuggy probably took these in New Zealand, where he lives.
Shuggy:
--- Quote from: Ellemeno on August 29, 2007, 09:38:31 pm ---I thought some people might not know that Shuggy probably took these in New Zealand, where he lives.
--- End quote ---
I did, and I'm lucky to live far from bright city lights.
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