LIGHT POLLUTION POLL

[nightfisher]

I have voted 100% as the available sky has various factors including a factory with 10 mega bright floodlights that illuminate the lower ecliptic path, and to the right is a new housing development .

In hindsight its probably a bit less but it does make things difficult for me, though it is better than a lot of peoples skies

[Stub Mandrel]

Back to the 70s? Bring back massive power cuts!

[Alfian]

Like others I'm not sure quite how to gauge this as the base line of truly dark skies, I assume, is not one I've experienced.  That said., I am very fortunate to live in a place which in itself is quite dark and located in blue area on the map. The nearest streetlight is  3/4 mile away, nearest neighbour 250 yards away, and no real major (industrial) light sources for a few miles.  However the low glow from Bradford/Leeds in one direction and Rochdale/Oldham/Manchester in the other ever present. That in itself is probably much better than many people have to contend with and on a good night  skies well above the horizon, which is where its at anyway,  can be very nice. The frustrating issue I often have though, is one of  mists from the surrounding  damp moors that rise to further illuminate and magnify the effects of LP. So how do I score this - On a good night  maybe 20%, on a misty night maybe 50+%. 

[TareqPhoto]

I am not sure how to measure or calculate that light pollution, but let's say i will pass this measurement, how good the visual will be in light pollution or how bad? i mean what objects can be seen and which can't if the objects aren't down by horizons? From my urban i can't see the milky way at all, not even a glance, also i can't see any nebula or any galaxy with scope or binocular, only planets such as Jupiter and Saturn if it is up, and very few stars almost Arcturus or Vega for example or the Big Dipper stars.

[Excelsior]

To measure light pollution this is what I do : 

- SQM (or SQML ) readings all nights you can see stars ( not with moon and not on milky way ),

- MvlonZ and MvlonUMI determination,

- Bortle scale

With this you can determine your sky quality ... and light pollution level.

[TareqPhoto]

57 minutes ago, Excelsior said:

To measure light pollution this is what I do : 

- SQM (or SQML ) readings all nights you can see stars ( not with moon and not on milky way ),

- MvlonZ and MvlonUMI determination,

- Bortle scale

With this you can determine your sky quality ... and light pollution level.

Ok, i hope to know or understand those words first then i will give it a try, and hope it won't request special devices or tools to do measurements. 

[laser_jock99]

If the option to put down 12% was available I would have put that. Even from the 'darkest' part of Mid Wales I can easily pick up the light dome from Birmingham 70 miles away.

You have to be a LONG way from towns and cities to be light pollution free.

[TareqPhoto]

Looking at those images, how or what do you think about the light pollution?

Taken from my house yard, the moon is not there as you know, ignore the dust on the sensor, what do you think?

[TareqPhoto]

I think in the winter it will be better view or cleaner sky due to washed sky from rain, ofcourse if there are no clouds, in the summer with haze and humidity i feel the light from the city is magnified or spread out.

[Excelsior]

1 hour ago, TareqPhoto said:

Looking at those images, how or what do you think about the light pollution?

Taken from my house yard, the moon is not there as you know, ignore the dust on the sensor, what do you think?

Hard to say ; to have an idea and to compare with other skies we must know many things on your photos like time of pose, what device do you use, this is one image or many stacked, a treatement ? ......

Ajman is close of Dubai; not so good for the sky quality.

PS : The SQM is a special device.

[TareqPhoto]

23 minutes ago, Excelsior said:

Hard to say ; to have an idea and to compare with other skies we must know many things on your photos like time of pose, what device do you use, this is one image or many stacked, a treatement ? ......

Ajman is close of Dubai; not so good for the sky quality.

PS : The SQM is a special device.

The time was really late, between 2am up to 2:25am.

I used Sony A7R and Samyang 14mm lens on Gitzo photography tripod, no tracking at all, no filters.

All of these are just one or single image, and they are processed in Photoshop [CC] only, no another software, and sounds i over processed them too.

[EWHB]

6 hours ago, TareqPhoto said:

Looking at those images, how or what do you think about the light pollution?

Taken from my house yard, the moon is not there as you know, ignore the dust on the sensor, what do you think?

I think that you are very luck to have decently dark skies!

Thanks for the post.

[TareqPhoto]

3 hours ago, EWHB said:

I think that you are very luck to have decently dark skies!

Thanks for the post.

I don't think that we have that dark sky, but I will give it a try

[DavidJM]

Really don't know how to gauge light pollution without maths, is there a good website, just know that the skies here are better than where I sued to live

[Stub Mandrel]

57 minutes ago, DavidJM said:

Really don't know how to gauge light pollution without maths, is there a good website, just know that the skies here are better than where I sued to live

When Orion is up you can estimate your NELM (Naked Eye Limiting Magnitude) with this guide (the numbers it gives are NELMs even though it doesn't say so).

 

[DavidJM]

7 minutes ago, Stub Mandrel said:

When Orion is up you can estimate your NELM (Naked Eye Limiting Magnitude) with this guide (the numbers it gives are NELMs even though it doesn't say so).

 

Thanks, that's really useful!

[Stub Mandrel]

15 minutes ago, DavidJM said:

Thanks, that's really useful!

Bear in mind that if (like me) you have a fair bit of low-down LP but a clear 'hole' above you you can see a lot more than that test might suggest when you look up.

[Starwatcher21]

i am lucky here in brentwood essex the local council turn the lights off at 12-1 am so it's perfect late at night.

[TareqPhoto]

I can't put the number according to that guide, but let's say if i can manage to see more than 5 stars, where that put me at?

I just went out and came back, those are the known ones i could see by my naked eyes: The Big Dipper, Arcturus, Vega, Spica, Kochab, Deneb, Altair, Sadr, Antares, acrab and the other two stars below it, i even managed to see Polaris now, and ofcourse little few stars i don't want to name them all.

So, what do you think about the light pollution in my yard? It is light polluted urban, but maybe my area isn't that much heavy LP, but definitely it is not low LP, not sure if it is also moderate, but i can't see any nebula or any galaxy by naked eyes, i think i can't see nebula by scope as well, part of the milky way is in the sky from my phone app but i couldn't see it from my yard.

In winter the view is better because the sky is more washed if the clouds are gone, now is good view a bit because the humidity isn't high yet, the moon is still in the beginning.

[Stub Mandrel]

8 minutes ago, TareqPhoto said:

and ofcourse little few stars i don't want to name them all.

You can only judge the LP by the faintest star you can see.

[TareqPhoto]

11 minutes ago, Stub Mandrel said:

You can only judge the LP by the faintest star you can see.

Is there a list of those faintest stars so i can judge?

Also, do you mean seeing by naked eyes or by scopes?

[Stub Mandrel]

Naked eye, see this wikipedia page:

https://en.wikipedia.org/wiki/Bortle_scale

[TareqPhoto]

If according to that table, then definitely not 4-4.5 NELM, i can say it is around 4.8-6 range, say it is 5-5.5 NELM almost, but does that means i should able to see the stars i mentioned above before?

Also the table mentioned if using telescope, let's say if i see about 5-10% of the stars in the sky in my yard, if i use my binocular  or the scope then i can see almost 30% of the stars, i mean the scope or binocular will definitely magnify the number of stars or the brightness because it is getting closer to view them than my eyes, i still didn't use some specific filters except the Skyglow & Moon filter which is nothing much to rely on, but i ordered UHC cheap filter for test, i will give it a try once i get it.

Now i am wondering, if i drove to a nearby zone that is almost in green/yellow or even orange zone, will i see better there? how far should i be away from any LP from any direction for better view?

As you saw from the photos i posted above, the camera or telescope can see more than what i see, and my mount is able to shoot longer exposure, so if i did shoot long exposure say about 2-5 minutes, will that help to blow out some hidden stars or faint objects?

[rockystar]

19 hours ago, TareqPhoto said:

As you saw from the photos i posted above, the camera or telescope can see more than what i see, and my mount is able to shoot longer exposure, so if i did shoot long exposure say about 2-5 minutes, will that help to blow out some hidden stars or faint objects?

It's all about gathering more light. Your eyes can only gather so much, put a telescope in the optical train, and you will see more stars because the telescope can gather more light, the bigger the aperture, the more light you can gather, the more stars you will see.

Similarly, if you leave a camera open for a few minutes, then it will gather even more light and show you even more stars.

[TareqPhoto]

2 hours ago, rockystar said:

It's all about gathering more light. Your eyes can only gather so much, put a telescope in the optical train, and you will see more stars because the telescope can gather more light, the bigger the aperture, the more light you can gather, the more stars you will see.

Similarly, if you leave a camera open for a few minutes, then it will gather even more light and show you even more stars.

And this is what i will do