How dark is dark enough?

[Alastair Rae]

If you check out the interactive Britain light pollution map with its LP colour coding, you'll see a big white blob in the SE which I've called home for the last 40 years. For a while now I've been thinking about moving out and my new-found interest in astronomy has introduced another factor to the planning process.

Astronomically it would be fantastic to live in one of the black zones but, well, for various reasons that's not going to happen. So my question is, in UK terms, what LP zone colour is dark enough for back garden star gazing? I've seen some great photos posted on SGL from non-rural areas so maybe I should pose this as two questions.

What colour zone is dark enough for visual DSO, say with big dob?

What colour zone is dark enough for imaging?

[Stargazer_00]

I live in Stevenage. Its up the A1. See that colour, I can see many DSO from my back yard. People in Stevenage do imaging. I met a bloke at the local club and he has done some quite nice images from a back yard with more direct LP than mine.

Also they are turning off all the street lights in Hertfordshire from 12-6am by the end of the summer. So that's a real + for the county.

[LukeSkywatcher]

I'm about 20 miles south of Dublin city and my area (which i consider pretty good as far as LP goes) is in a yellow spot. In saying that, my back garden is shielded on three sides from any major LP from streetlight etc. My view south is hampered because there is terrible glow from a dual carraige way a couple of miles away.

I have seen DSO with my 8" scope from this location and also imaged planets,starfields,galaxies etc without the use of a scope.

So yellow works for me.

Hope this helps somewhat. ALL LP though really is local and cant be compared easily.

I'm roughly located where the black line goes through the yellow zone on the east coast just below the bright lights of Dublin city: Given the choice i would be out on the west coast in the black zone (Connamara).

I do also use a SWLPF when observing. It helps a lot.

[sologuitarist61]

If you check out the interactive Britain light pollution map with its LP colour coding, you'll see a big white blob in the SE which I've called home for the last 40 years. For a while now I've been thinking about moving out and my new-found interest in astronomy has introduced another factor to the planning process.

Astronomically it would be fantastic to live in one of the black zones but, well, for various reasons that's not going to happen. So my question is, in UK terms, what LP zone colour is dark enough for back garden star gazing? I've seen some great photos posted on SGL from non-rural areas so maybe I should pose this as two questions.

What colour zone is dark enough for visual DSO, say with big dob?

What colour zone is dark enough for imaging?

Don't take too much notice of the light pollution map, as you say it shows the SE as all light polluted, yet I have relatives living in the middle of East Sussex, who get magnificent skies on a clear night, with the Milky Way easily visible. It is just a matter of getting far enough away, or in my relatives case, some low hills that get rid of the obvious illumination from nearby towns.

I am a bit suspicious of such things, as they are done by people with an axe to grind. It is like the images from space looking down on North America where the Eastern seaboard is a white out, yet there are areas there that have dark skies too.

It is a matter of exposure, give it twenty minutes and the white-out will be greater than one minute - everything is relative in photography

and yes, the camera does lie - frequently

Light pollution is a terrible problem for us all, but don't take these maps at face value.

[Chris]

I've just checked and I'm in the red zone in Ipswich, I've had no problems imaging, but I tend to go for objects with a bit of elavation which helps, I've only just got an LP filter which I've not tried yet but it can only make things even better. Don't let the map put you off:)

[x6gas]

Light pollution is a terrible problem for us all, but don't take these maps at face value.

Agreed

More tricky for visual, but for imaging you can get away with quite LP skies if you are using filters... especially narrowband.

I've been amazed at what I've got under cacky conditions with an Ha filter...

[umadog]

It's not that the LP maps are wrong but that they are low resolution. So it's quite feasible for there to be a small island of darker skies embedded in an bad area. The US eastern seaboard is not a white-out on the LP map: http://astro-observer.com/dark/lpmapusa.html The biggest white area is NYC. There are plenty of areas which are yellow (tolerable skies) or better, and plenty of these are 2 hours drive of NYC.

The reason why you should take the LP map seriously is this: http://www.wired.com/wiredscience/2011/03/light-pollution-map/ LP is getting worse and the small islands of nice skies (particularly those that are so small they aren't even on the map) are likely to be the first to go. Go for somewhere that's on the edge of the light pollution and that has relatively good access to yet darker skies. Unless you move to a farmhouse in the middle of Wales you won't be getting the darkest skies, so you will want to get to darker from time to time. It makes sense to make that easy for yourself.

[swamp thing]

Light pollution from large cities like London extend for over 100 miles.

Shocking I know but true. To get away from sky glow in England is very difficult. So for most of us some degree of LP is mandatory. I live in south London and make do by transporting my scopes out into more rural areas when observing. For most clear nights this means a half hour drive to what I would call acceptable levels of LP for most observing. This site the summer milky way is easy enough and all the main stars in Ursa minor are visible

For darker skies an hour out of London provides me with some pretty good sites. These can show the winter milky way nicely and the Cygnus rift is easy peasy. Even objects like the veil nebula are non filter objects.

But for excellent skies your gonna have to travel a really long way, I use some sites in mid Wales. The difference between these and even the ones an hour out of London is nothing short of spectacular.

The only trouble with travelling so far is the wonderful unpredictable British weather.

[JamesF]

I believe the avex-asso map is partly modelled from population density which can give a misleading impression. A village a mile or so from me for example shows up quite brightly, yet it has no streetlights and perhaps only thirty houses. If the LP were as bad as that map suggests I'd certainly be able to see it from here, but there's no sign of it.

James

[Alastair Rae]

I believe the avex-asso map is partly modelled from population density which can give a misleading impression. A village a mile or so from me for example shows up quite brightly, yet it has no streetlights and perhaps only thirty houses. If the LP were as bad as that map suggests I'd certainly be able to see it from here, but there's no sign of it.

James

Maybe the map is not 100% accurate but I'm guessing it's better for the more built up areas. What I'm trying to find out is what standard of astro can people in red or yellow zones achieve from their back gardens.

[laser_jock99]

Unless you move to a farmhouse in the middle of Wales you won't be getting the darkest skies, so you will want to get to darker from time to time. It makes sense to make that easy for yourself.

I live in the dark spot in the middle of Wales and even here it is not LP free. The all pervading sky glow from the Midlands conurbation 80 miles east is apparent on long exposure photos towards the eastern horizon. I processed some photos recently, shot through thin high cloud (altitude ~20,000 feet) and these are clearly underlit by LP from local towns (towns 25 miles away!).

LP on high cloud- Milky Way visible behind.

[boltzy]

I live in south London and make do by transporting my scopes out into more rural areas when observing. For most clear nights this means a half hour drive to what I would call acceptable levels of LP for most observing.

How do you find suitable sites? I'm in south east London (on the edge) and have been wondering about where I could go to escape the LP.

Mark

[Ant]

When we moved (from Canvey Island, Essex (red on the map)) I did quite a bit of driving around for darker skies.

Luckily my wife found a little village she liked and it happens to be quite dark...

The attached image shows roughly where we are - right at the southern edge of the village. The milky way is easily visible most nights the moon isn't out. Double Cluster/M31 easy naked eye... I'm sure that I got a hint of M13 as well naked eye!

Saying all of that, there is still LP. and can be seen clearly when cloud is around. This video show a very short animation of high cloud going over - and this is South for me.

iRQQvABabh8

Here is a still image from the same sequence.

This is a RBG image with 10 minute subs and no LP filter.

What I'm trying to get across is that almost anywhere you go there is still going to be some LP. Clearly the further away from the reds and oranges you get the better...

Ant

[Ad Astra]

Don't forget that there are lots of targets beyond deep sky nebulae and galaxies. Double stars, globulars, Lunar and planetary work don't require particularly dark skies. In fact, when my class does lunar observations, we usually work on the lighted patio outside my class rather than lug the telescopes half a km to the football pitch for darker conditions.

Enjoy the sky you have, and save the deep sky stuff for when you get to go out someplace more remote.

Dan

[umadog]

For sure everywhere you go is going to be light polluted to some degree, but if you can get to Bortle 3 or better then you're going to be very happy.

[rory]

ive done all my visual from my garden in a large town (on the border between red and orange). ive found it okay for me personally at the moment. it depends on what you want to see. galaxies for me are resrticted to the brighter ones ,and even then ,nothing more than small grey smears.

but o/c and globs, some nebula are fine. planets are also fine.

some nights youll have clear sky and all is nice and transparent.other clear nights are a mushy orange skyglow. something to do with reflecting particles from the surrounding lights. thats when it gets a bit tough.

ive not been to a dark loc as yet, probably because once i do.i'll 1/ want to move house . 2/ never stop complaining about my garden skies !

[squeaky]

I've just checked and I'm in the red zone in Ipswich, I've had no problems imaging, but I tend to go for objects with a bit of elavation which helps, I've only just got an LP filter which I've not tried yet but it can only make things even better. Don't let the map put you off:)

I'm in Claydon.

Me too with the elevation thing. Forced by being surrounded by trees! I'm also down in a dip. Much of my horizon STARTS at 20°

Just beginning on imaging and I think I'm managing to make absolutely every mistake in the book - starting with buying the wrong camera

Could you do me a favour please? take a look at this page: http://www.squeaky.org.uk/d3100/

.. and then tell me do you have to do all that sort of thing with a Cannon?

[squeaky]

Maybe the map is not 100% accurate but I'm guessing it's better for the more built up areas. What I'm trying to find out is what standard of astro can people in red or yellow zones achieve from their back gardens.

I'm in the middle of the orangy-red zone in Claydon, Suffolk.

This thread: Ursa Major shows my first ever wide field photo, first as raw untreated - and as the thread goes on the results after a bit of processing. For first efforts I don't think that's too bad.

Got an LP filter coming - so that should improve things, and I still haven't had chance to piggy back for tracking, and to make a stacked set. All of which should improve that shot a great deal.

The camera in my local conditions was picking up mag 9.5 stars in its own lens (not via the telescope) at a time when I was struggling to see mag 4 and as yet I have no idea how I'll do through the EP. So light pollution? Hmm... not a good thing, obviously, but you can still get good results in "poor" areas. Good ain't perfect, I know, but if I'm going to move house for better skies it'll be to Norway, or Canada, or Alaska

[cotterless45]

We live in a Middle Earth town.Seeing conditions vary so much, but there's a lo glow around. Last night we could see Bode's ,M101 and M97 by eye.It's a challenge and clear dark nights are rare.I've seen some of our blackest skies in the Western Isles and it's difficult to describe being unable to pick out constellations due to the multitude of stars. I just feel that with all our light pollution we've lost so much.

If you can get to the darkest sight that you can , you'll see so much,even by eye or with a small scope.

[swamp thing]

How do you find suitable sites? I'm in south east London (on the edge) and have been wondering about where I could go to escape the LP.

Mark

I use maps like the ones shown on this thread. I also look on normal maps to find places that are furthest away from any buildings.

Then use google maps to go have a look before I even think of driving there. If all looks good I'll drive there.