Tell us your sky quality

[ApophisAstros]

On 02/05/2019 at 09:28, geoflewis said:

I also vote for more clear (and moonless) skies, but not sure if I want to give up my bortle class.....?. Here's a series recent of readings off my iPhone using the DSM app, which average at the lower end of Bortle 3, but with several readings in the Bortle 2 range. I usually take 4 readings one after the other pointing towards the zenith, but facing roughly E,S,W,N in sequence. The actual phone camera angle (90 deg being vertical) is shown, so somewhat less than the zenith and generally tilted slightly in the direction I'm facing.

Is the phone screen on when you do this?

Roger

[ApophisAstros]

On 02/05/2019 at 14:23, hadyn42 said:

Hello Guys

Just submitting my pennies worth. I live just on the outskirts of Douglas in the village of Onchan Isle of Man.

 

Regards,

Hadyn - Isle of Man

 

 

amazing i am the same as you on the main land , southern england.Thoght you would be much better being a small island?

Roger

[ApophisAstros]

On 22/05/2019 at 13:57, Paul73 said:

Namibia here we come!

There is no toilets,water and the insects are HUGE🦟and the flies lay maggots in you that you only know about when you get home,  probably eating its way out.

Roger

[Chris]

I think I'm Bortle 5/6 where I am, so could be worse!

[ApophisAstros]

15 minutes ago, tingting44 said:

right, well according to the FLO site my home in southampton is bortle 6

my dark spot at the new forest is bortle 4 which is about a 30 minute drive away

 

EDIT, been going through this map, its amazing to see like this how much of the earth we are polluting with light, i can only imagine what them countries with grey bortle 1 look like

 

"its amazing to see like this how much of the earth we are polluting with light"

Thats the half of it.........people, plastic,rubbish,..........

Roger

[geoflewis]

19 minutes ago, apophisOAS said:

Is the phone screen on when you do this?

Roger

Yes, otherwise I couldn’t use the app. It’s a black screen with red writing like this...

You take a dark frame first then point the camera at the zenith to take a sky exposure.

[MarsG76]

20 minutes ago, geoflewis said:

Yes, otherwise I couldn’t use the app. It’s a black screen with red writing like this...

You take a dark frame first then point the camera at the zenith to take a sky exposure.

Looks like a useful app.. thanks for the tip.

 

[scarp15]

I have not measured the sky brightness from home. Not something that has ever inspired me to do although my back yard is OK if for observing brighter DSO's. Where I prefer to be, becomes a completely different attitude. My Unihedron Sky Quality Meter -L device, an important tool for informing a frequency of readings, to gauge an average upon different locations based on overall sky conditions. Theses can vary marginally between different trips. Along the Scottish border in North Northumberland, I will take readings of 21.5 during early dark evening periods, but have yet to be able to have clear transparent enough dark skies for later and early morning, when able to take readings potentially attaining 21.6 -21.7 mag. I heed little attention to online sky brightness map references, too generalised and oft overstated.  

[geoflewis]

Just now, MarsG76 said:

Looks like a useful app.. thanks for the tip.

 

Yes, it’s useful, but clearly it is not as sensitive as a dedicated SQM-L meter. I exchanged emails with the developer a couple of years ago and he advised that the iPhone 6 camera is not reliable beyond about 21.5, so there is a need to take any readings lower than with caution. On several occasions I’ve got a reading of ‘Invalid’, which means the sky was too dark for the app to interpret. The readings I get are broadly consistent with LP maps for the area where I live, so with those reservations I consider it a useful app, sufficient for my needs.

[MarsG76]

1 hour ago, geoflewis said:

Yes, it’s useful, but clearly it is not as sensitive as a dedicated SQM-L meter. I exchanged emails with the developer a couple of years ago and he advised that the iPhone 6 camera is not reliable beyond about 21.5, so there is a need to take any readings lower than with caution. On several occasions I’ve got a reading of ‘Invalid’, which means the sky was too dark for the app to interpret. The readings I get are broadly consistent with LP maps for the area where I live, so with those reservations I consider it a useful app, sufficient for my needs.

To me that looks like a very good review of this app.. considering the cost of only $2.99 and as you say that it's consistent with your area, only failing when it's too dark... tells me that it'll be accurate enough for 9/10 locations and those times when it displays "Invalid", you know that you're in a very dark spot.... 

[ApophisAstros]

4 hours ago, geoflewis said:

Yes, otherwise I couldn’t use the app. It’s a black screen with red writing like this...

You take a dark frame first then point the camera at the zenith to take a sky exposure.

Be interesting to see how it compares next to a SQL meter at the same place.

Roger

[geoflewis]

6 hours ago, apophisOAS said:

Be interesting to see how it compares next to a SQL meter at the same place.

Roger

I agree and have often wondered that, but never thought about it when someone was available who had one to hand. When I asked the developer Norbert Schmidt about it his reply was, 'the Unihedron is better, but the app comes close and reaches more people'. My understanding is that the app was originally developed as a citizen science project tool to get a world wide audience to participate in monitoring the quality of the night sky, without them having to purchase a fairly expensive piece of kit that has no other purpose.

[groberts]

Interesting thread - I live just north of Gatwick airport and according to the aforesaid light pollution map this is Bortle 5 SQM 19.84, though I suspect that in the early evening when the airport lights are fully on looking south it's more like Bortle 6, cerainly no chanace of seeing the Milky Way.

However, in this era of Covid-19 lockdown my eyes, imaging and guiding tell me we really are benefitting from less light and cleaner skies.  I wonder if anyone has any emperical data to support this from their location?

Graham   

[OzzyUK]

This is my location.

 

I live quite close to the South Downs and Beachy Head too which is classed as a dark sky site but still shows as fairly high on the Bortle scale compared to some places.

[robhatherton]

I live south of Nantwich in Cheshire and its Bortle 4. If I go a couple of miles towards Nantwich or Crewe it soon becomes Bortle 5 then 6. By the way the Clear Outside app from FLO will give you this information though I think the map is great for letting you know where to go for an improvement.

[scarp15]

19 hours ago, Ships and Stars said:

At 'the ranch' various sites say 20.65 to 20.70, but I've never seen it over 20.42 with the SQM-L and that's with all local business lights off which is highly unusual.

20.20 to 20.35 is as good as it gets, unless it's an exceptional night.

Beyond home, I have code names for my dark sky sites 🤣 (I know, I know...)

Dark Sky Charlie is c. 21.4 and is only about 20 minutes away, the difference from home is massive. Like doubling the aperture.

Dark Sky Bravo is c. 21.55 to 21.60+ about 35 minutes away, brilliant. Saw (or 'detected') the HH through the 12" dob there without much fuss.

Then there's 'Dark Sky Alpha', which I've only been able to measure once. It was 21.85, but I'm sure it would easily crack 21.90 on some of the nights I've been there.  It's dark enough there you can easily detect light on the horizon from an urban area 75 miles away.

Therefore home is a bit of a struggle compared to what's relatively close by, and once the businesses open back up (they were closed before the outbreak) then it's pretty much game over for visual from home. 

I like the codes Robert 👍, impressive SQM readings to. My new dark sky location is close to Carter Bar on the Scottish border, a location where there had been past skirmishes / battles between English and Scotch farmers. An area also noted for the lawless Border Reivers. In our time though for encountering Osprey, so 'Dark Sky Osprey' I think. 

[miguel87]

1 hour ago, scarp15 said:

 'Dark Sky Osprey' I think. 

D.S.O.

[scarp15]

6 minutes ago, miguel87 said:

D.S.O.

👍🙂

[Ships and Stars]

2 hours ago, scarp15 said:

My new dark sky location is close to Carter Bar on the Scottish border, a location where there had been past skirmishes / battles between English and Scotch farmers. An area also noted for the lawless Border Reivers. In our time though for encountering Osprey, so 'Dark Sky Osprey' I think. 

Dark Sky Osprey (DSO) love it! Sounds like a good location there on the border. Last night was end of astro darkness, but I did notice a week ago with the unihedron I was still getting largely the same reading an hour after astro darkness was supposed to end, so perhaps I'll be able to view a little over the summer. 

[miguel87]

2 minutes ago, Ships and Stars said:

Dark Sky Osprey (DSO) love it! Sounds like a good location there on the border. Last night was end of astro darkness, but I did notice a week ago with the unihedron I was still getting largely the same reading an hour after astro darkness was supposed to end, so perhaps I'll be able to view a little over the summer. 

Good to know. I always assumed that the black section on clear outside represented astronomical darkness.

[Ships and Stars]

3 minutes ago, miguel87 said:

Good to know. I always assumed that the black section on clear outside represented astronomical darkness.

Hi Miguel, it does, but it seems that perhaps an hour each side is still dark enough for a quick look through the scope. I'm near Aberdeen, so fairly far north. Last night we had 1.5hrs astro darkness, but after this moon phase, that will be gone until late August here! I'm still going to try over the summer, but only with the smaller dob and binoculars.

[miguel87]

5 minutes ago, Ships and Stars said:

Hi Miguel, it does, but it seems that perhaps an hour each side is still dark enough for a quick look through the scope. I'm near Aberdeen, so fairly far north. Last night we had 1.5hrs astro darkness, but after this moon phase, that will be gone until late August here! I'm still going to try over the summer, but only with the smaller dob and binoculars.

Aaah my bad, I didnt think about geographic location. I'm gonna have to skip ahead on my clear outside and see when if my darkness stops down here at 51.6 degrees north!

Edited April 29, 2020 by miguel87

[Ships and Stars]

35 minutes ago, miguel87 said:

Aaah my bad, I didnt think about geographic location. I'm gonna have to skip ahead on my clear outside and see when if my darkness stops down here at 51.6 degrees north!

Have a look online at the 'suncalc' website and equally 'mooncalc', both really handy. Best viewed on a pc or laptop. I use those two frequently.

[Xsubmariner]

The site shows my location as Bortle 4, so not too bad. Unfortunately imaging does suffer from Wye valley mist on some of the scarce clear nights.

[miguel87]

40 minutes ago, Xsubmariner said:

The site shows my location as Bortle 4, so not too bad. Unfortunately imaging does suffer from Wye valley mist on some of the scarce clear nights.

I used to observe at garway and skenfrith not far from there. Great part of the world!