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Poita
13-03-2012, 10:57 AM
I'd love to see what everyone's light pollution is like.

I was wondering if those of us with DSLRs could take a wide shot of the night sky over our observing sites, perhaps all using the same ISO, exposure time and F-Stop, and then post them here.

Any suggestions as for the settings?

Ric
13-03-2012, 11:59 AM
No LP for me

I'm fortunate to live in a dark sky area.

Poita
13-03-2012, 02:50 PM
Even better. That would give us a reference frame :)

How about 30 seconds, ISO 800 and F5.6?

Most camera/lens combos could handle that.

Barrykgerdes
13-03-2012, 02:54 PM
Visibility (moonless night) Northwest Sydney outer metropolitan just makes 4th magnitude. ( need my long distance glasses to correct my mild miopia)

Barry

BPO
13-03-2012, 03:30 PM
Yep, same. And I don't take it for granted.

koputai
13-03-2012, 03:48 PM
Most of us will have varying LP depending on which direction we point the camera. In Sydney's Northern Beaches, my North and East is pretty good, West is bad, and South is very bad.

Maybe we need 5 shots each. North, South, East, West, and straight up.

Is there a PC application out there that can stitch heaps of shots together to make a hemispheric projection like the star charts in the middle of astro magazines? That would be interesting.

Cheers,
Jason.

DavidU
13-03-2012, 04:02 PM
so this is the settings we are going to use?

ballaratdragons
13-03-2012, 05:24 PM
Too many variables to compare.

To compare everyones image you would need to match everything: How much Moon phase? Seeing? Transparency? Low distant cloud reflecting skyglow? etc etc.

The results would be interesting but the variables are the problem.

LP can actually change by the hour on some nights.
I suppose in Cities it is always the same. Bright.
But in the country it is either dark, or darker, with the occasional reflection under the clouds of distant light.

acropolite
13-03-2012, 05:50 PM
here is mine posted late last year, the city is around 10KM to the south east, the closest lights are just a few Km away. The night sky from my backyard is still OK, despite the LP I can still make out the LMC and SMC naked eye.

http://www.iceinspace.com.au/forum/attachment_browse.php?a=106270

bartman
13-03-2012, 06:31 PM
Love the idea and I would like to start it off with three pics I took whilst trying to capture that elusive Aurora....

And to add to that I like the suggestion Jason has made too below....

LP1 is 24mm|20 sec|f5.6|iso 800
LP2 is 10mm|20sec|f5.6|iso 1600
LP3 is 20mm|53sec|f5.6|iso 250
all on my nikon d90, no adjustments in ps, just resize.
Taken about 22:00 11.03.2012, facing directly south. Midland would be directly south and Perth slightly to the right of the pic. Midland is about 20 km south of this point.
When I look at the NEF ( raw) pics its a lot worse...but then you would make adjustments hey?
The light in the fore ground is from flood lights and the moon :)
Bartman

mithrandir
13-03-2012, 06:38 PM
Hugin or AutoStitch if you want to try a freebie, but I'm not sure about hemispheric projections. AutoPano Pro if you don't mind the "moderate" price. AutoPano Giga if you want to be able to handle huge panoramas.

I agree on the varying LP. Out my way North East through North West is sort of OK, West is passable until you get to the Penrith skyglow, the rest is very bad.

I can try some shots from the showground where I don't have all the problems at home. The trees don't a) block the view and b) reflect all the sodium vapour from the main road.

With an 11mm lens in portrait that is only 6 to 8 frames, but the zenith might not stitch well.

ballaratdragons
13-03-2012, 07:26 PM
OK, I'll join in. :)

Taken on a clear night, no Moon, facing south :thumbsup:

BPO
13-03-2012, 08:03 PM
Nice! :thumbsup:

Shame about the snakes, though. :D

JB80
13-03-2012, 08:30 PM
Oooh, I should be good at this. LP is terrible here.
When it clears up I'll have a go.

ballaratdragons
13-03-2012, 08:51 PM
:lol: Funny about that. I have lived here for 10 years and seen 3 snakes. And that's all.
I saw more than that in the suburbs :lol:

mithrandir
13-03-2012, 11:04 PM
Castle Hill Showground ~21:00 AEDT (after astronomical twilight). Frame centre left is east towards Castle Hill, centre right is towards Parramatta. Sydney is more or less in between them. 16 frames @ 30 sec, f5.6, ISO 800.

The floodlights - not at all LP friendly - are for the Council Chambers and Hills Centre car parks. They are setting up for the 126th Castle Hill Show this weekend so there are a few more lights than usual. A few "orbs" from the bright lights.

The SQM for the zenith at home at 23:00 AEDT (400m from the photos) is 19.08.

Stitched in AutoPano Giga.

asimov
13-03-2012, 11:11 PM
Zero where I am.

Poita
14-03-2012, 09:12 AM
I'll take some pics tonight before the moon comes up. Shooting in each direction is a great idea.

Even people with no light pollution, take a shot in each direction and make us jealous.

Poita
14-03-2012, 09:16 AM
I guess it would be best to have no moon, or take a shot before the moon rises.

Seeing and transparency aren't going to matter all that much for a 30s shot with a wide shot. It is more just to get an idea of what everybody deals with in their backyards. It is also then interesting to look at the same people's astro photos knowing what their LP is like.

But really, it is just an excuse to see some new photos and get to know everyone better.:)

Poita
14-03-2012, 09:25 AM
Sure, why not :D
But I did pull it out of my bu.. err hat, so if anyone has better settings, speak up now or forever hold your peace.


Oh, and re the panorama question asked earlier, great page here on how to shoot them.
http://www.cambridgeincolour.com/tutorials/digital-panoramas.htm

Vasya Pupkin
07-07-2012, 09:09 PM
Excuse me for my strange question. I am from Russia, so I can’t see an answer by myself. Tell me please, what constellations you can see in 4 seasons. This question is here because it can be that some constellation is even in zenith, but you can’t see it because of its darkness (for me it is Lynx in winter). But, of course, you have such constellations that can be such a symbol of a season (it is clear for observing).