Summer Night in Astronomy Town (2009 Sept 12)

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Expand view Topic review: Summer Night in Astronomy Town (2009 Sept 12)

Re: Summer Night in Astronomy Town (2009 Sept 12)

by rigelan » Sun Sep 13, 2009 11:53 pm

Thanks Chris, much appreciated.

Not being an astro photographer myself, it is difficult for me to have a point of reference.

Re: Summer Night in Astronomy Town (2009 Sept 12)

by Chris Peterson » Sun Sep 13, 2009 9:24 pm

rigelan wrote:
Chris Peterson wrote:Nevertheless, if you're in a dark location, an exposure long enough to bring out this type of sky leaves the foreground completely dark.
Got an example picture? I mean if the foreground for milky way pictures is not typically this bright, what is a typical brightness for a nearby foreground?
This is what Milky Way images look like from my house, which is under very dark skies:

Image

Basically, the surrounds don't pick up enough light from the sky background to record as anything other than black. That's what any Milky Way shot will show from a dark site, since the only light source available to illuminate the hills and trees is the sky itself, which will always be much brighter than anything reflecting it.

Re: Summer Night in Astronomy Town (2009 Sept 12)

by Ayiomamitis » Sun Sep 13, 2009 7:48 pm

Dear group,

I am posting the following reply on behalf of Babak Tafreshi, the photographer behind the photo of interest, with the hope it will answer any questions people may have:

"The image is made with 30 seconds exposure at f2.5 and ISO1600, it is enough to illuminate the foreground even with lights of a little town. The town's light pollution is not much as the Milky Way appearance tells. However I agree there is little too much light on the foreground which came from the main road (near to my location)."

Re: Summer Night in Astronomy Town (2009 Sept 12)

by rigelan » Sat Sep 12, 2009 3:37 pm

After perusing our milky way images, it seems most are taken out in the middle of nowhere.
Sahara
Badlands
Mauna Kea
Devils Tower
Sequoia National Park

Well I suppose here's one with a foreground shot that's near a town

http://antwrp.gsfc.nasa.gov/apod/ap080905.html
Chris Peterson wrote:This APOD is a lovely image, but there's something wrong if a place called Astronomy Town is putting out enough stray light to illuminate the surrounding landscape so strongly!
I'll agree with the original poster, compared to APOD's other images, today's foreground does seem quite bright.

Re: Summer Night in Astronomy Town (2009 Sept 12)

by apodman » Sat Sep 12, 2009 3:31 pm

rigelan wrote:
Chris Peterson wrote:Nevertheless, if you're in a dark location, an exposure long enough to bring out this type of sky leaves the foreground completely dark.
Got an example picture? I mean if the foreground for milky way pictures is not typically this bright, what is a typical brightness for a nearby foreground?
http://antwrp.gsfc.nasa.gov/apod/ap080729.html

Re: Summer Night in Astronomy Town (2009 Sept 12)

by rigelan » Sat Sep 12, 2009 3:23 pm

Chris Peterson wrote:Nevertheless, if you're in a dark location, an exposure long enough to bring out this type of sky leaves the foreground completely dark.
Got an example picture? I mean if the foreground for milky way pictures is not typically this bright, what is a typical brightness for a nearby foreground?

Re: Summer Night in Astronomy Town (2009 Sept 12)

by bystander » Sat Sep 12, 2009 3:21 pm

Arizona Sky Village: Astronomy Town, USA
Arizona Sky Village: A Town Built for Astronomy Lovers
25 July 2007 by New Scientist Space and Reuters

Re: Summer Night in Astronomy Town (2009 Sept 12)

by Chris Peterson » Sat Sep 12, 2009 3:19 pm

rigelan wrote:Of course the city is not actually putting out as much light as appears in the picture. The camera shutter is open for many seconds. The sky shows the Milky Way during those many seconds of exposure, and the ground shows the shadows of the nearby town after many seconds of exposure.
Nevertheless, if you're in a dark location, an exposure long enough to bring out this type of sky leaves the foreground completely dark.

Re: Summer Night in Astronomy Town (2009 Sept 12)

by rigelan » Sat Sep 12, 2009 3:13 pm

Yeah, I figured all the regulars around here DID know that. But no one had actually mentioned it in this thread, so I thought I'd mention it for the casual reader.

Re: Summer Night in Astronomy Town (2009 Sept 12)

by geckzilla » Sat Sep 12, 2009 3:10 pm

Rigelan, we know that. Even knowing that, it still seems like a lot of light pollution for a little town. Or as neufer mentioned maybe it's moonlight. If it were my photo I'd probably abuse my artistic license and darken the ground digitally.

Re: Summer Night in Astronomy Town (2009 Sept 12)

by rigelan » Sat Sep 12, 2009 2:55 pm

Of course the city is not actually putting out as much light as appears in the picture. The camera shutter is open for many seconds. The sky shows the Milky Way during those many seconds of exposure, and the ground shows the shadows of the nearby town after many seconds of exposure.

The picture appears surreal, but it a very lovely juxtaposition of colors.

Re: Summer Night in Astronomy Town (2009 Sept 12)

by geckzilla » Sat Sep 12, 2009 1:21 pm

Wikipedia says that one time, they turned off all the electricity to observe an astronomical event. Hmmm, it's hard to imagine the town itself can give off that much light since it is so small. Maybe he took that photo right next to a house, which could be relatively impressive.

edit: he doesn't live there, actually. Fixed post. Btw, here is a photo of their observatory: http://www.mssimmons.com/ms/Iran/Iran20 ... atory.html

the Valley of the Pistacia

by neufer » Sat Sep 12, 2009 1:21 pm

http://www.lakesideministries.net/1stCovenant/Isaiah/Isaiah_Images/IsaPict_Terebinth.htm wrote:
<<It is unfortunate that the word for this tree is translated in so many different ways.
For example, the tree under which King Saul was buried (I Chronicles 10:12) is termed
  • "the great tree" (NIV)
    "oak" (KJV and NASB)
    "terebinth" (JND)
Of these three terms, terebinth is the more accurate as one of the species of pistacia, although a species that does not occur in the Middle East, is frequently called terebinth.

In I Chronicles 14:14, the same tree is called "balsam" (NIV), and "mulberry" (KJV and JND).

The tree in which Absalom caught his head, not his hair as is often misquoted, (II Samuel 18:9) is a "large oak" (NIV), "great oak"(KJV), and "great terebinth" (JND).

So what is a terebinth or, more correctly, pistacia?

Two species occur in the Middle East, the Atlantic pistacia, Pistacia atlantica
and the Palestine pistacia, P. palaestina.

Atlantic pistacia is the larger of the two and therefore assumed to be the one referred to in the Scriptures although it is not possible to precisely label the species. When undisturbed (a rare occurrence in the Middle East) the trees reach a very large size and can live up to one thousand years. The Atlantic pistacia is recorded as the largest tree in Israel in recent history. Pistacia develops a very deep and extensive root system and therefore remains green even in years of drought. It often sprouts from the stump after being cut, as noted in Isaiah 6:13.

Additional references to pistacia are found in Genesis 35:4, Judges 6:11, I Chronicles 10:12, Isaiah 6:13 and 44:14. Because of its large size and great age, pistacia trees were well-known landmarks and were used as memorials for the dead, a practice followed until recently in some Arab villages. But the pistacia trees also became the object of idolatry (Hosea 4:13). Did Jacob bury the idols under the "oak" of Shechem because the tree was an object of veneration in itself?

As often in Scripture, great trees are associated with great men.
  • Gideon was by a large pistacia when he was called by God (Judges 6:11).
    David faced Goliath in the Valley of the Pistacias (I Samuel 17:2) (elah in Hebrew).
    Absalom, great in his own eyes, was trapped in a large pistacia.
The small, hard fruits of the P. palaestina are sold in Arab markets as a condiment.
They have a somewhat resinous taste and are known as butim in Arabic.>>

Re: Summer Night in Astronomy Town (2009 Sept 12)

by orin stepanek » Sat Sep 12, 2009 1:18 pm

The foreground landscape, illuminated by Astronomy Town lights, includes a kind of wild pistachio tree common in the region.
It does indeed, make you wonder how the photographer got such a good picture of the Milky Way with so much light pollution from Astronomy Town.

Orin

Re: Summer Night in Astronomy Town (2009 Sept 12)

by nujjer » Sat Sep 12, 2009 9:22 am

:-) I thought that too.

What I did like was the HOVER-OVER feature of the photo. When I look at pictures marked with constellations my brain focusses on the lines and words not the dots, so it's difficult to then look at the sky , which strangely doesnt have the benefit of lines and words (!), and identify constellations.

Anyone know of a constellation application that has the hover-over feature (or similar)

NUJ

Summer Night in Astronomy Town (2009 Sept 12)

by Chris Peterson » Sat Sep 12, 2009 4:05 am

This APOD is a lovely image, but there's something wrong if a place called Astronomy Town is putting out enough stray light to illuminate the surrounding landscape so strongly!

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