What difference does a very dark site make for astrophotography? A LOT! Wow!

[MKHACHFE]

Hi all, 

I recently had the pleasure of spending a week up in the Scottish Highlands. Where we were staying is rated at B2 on the light pollution map, but we all know that that map is overly generous ,so lets call it B2.5-B3. I was also unbelievably lucky and had most nights crystal clear and therefore managed to do some AP with my basic kit.  This consists of a Star Adventurer Mini, a wobbly £30 quid tripod and a Canon 4000D with a 70-300mm F5.6 lens.

I wasted a couple of nights just experimenting and taking subs of the various targets i had already imaged back home on the outskirts of Greater London, which i would say is B6 on a good night. I can see the MW occasionaly, but only as an exceptionally faint bit in the sky. In Onich, I would say that it was a major presence in the sky as opposed to a dim feature. I can't even imagine what it must be like in the Southern Hemisphere where they get the galactic core overhead. 

I wont bore you any more, but suffice it to say that the image below is a comparison between a 30s 1600ISO image taken at home and one from Onich. I know they are not in focus, i just used the first images i found on my drive to show you. They are also not the same target, but are pretty much the same elevation in the sky. 

Amazing difference. I took one or two 30s subs of M31 and got as much detail in 2 lights as i did from an hour and a half's worth back home, but obviously there is to much noise with only two sub to be useable. Still, the detail was clearly there. There Horsehead also showed up in one 30sec sub, which suprised me. 

So, all you relative newbies like me, if you can get somewhere even a bit darker than where you normally image from...GO!

 

[Sunshine]

That’s an unbelievable difference, On the left side there is more light pollution than anything else, a glaring difference.

[Budgie1]

The MW is very clear up here, more so on a crisp winter evening.

I live about a mile from Onich and far enough from Loch Linnhe to not be effected by the low cloud which forms on clear nights. I can see the LED street lights from Fort William if it's cloudy but there's no sign of them when it's clear. I recently got a ASI120MM Mini as a guide camera and connected it to a 9x50 finder, when I was imaging M51 a couple of weeks ago I could make out the centre of the galaxies on the PHD2 screen with a 2 second image update from the 120MM.

When are you coming back up?

[tomato]

Yup, a good dark sky location is worth a lot for broadband imaging,  you can use filters to assist you with eliminating light pollution but a proper dark sky will always have the edge.

[kirkster501]

It is a night and day difference.  The quality of the subs is in a different league altogether and faint detail is not washed out by the LP.  LP filters can only do so much, despite the claims on their wavelength charts.  Even with NB some LP leaks into even very tight bandpass filters, even 3nm ones.

[MKHACHFE]

23 hours ago, Sunshine said:

That’s an unbelievable difference, On the left side there is more light pollution than anything else, a glaring difference.

I know 😕

I'm so over living near London.

[MKHACHFE]

13 hours ago, kirkster501 said:

It is a night and day difference.  The quality of the subs is in a different league altogether and faint detail is not washed out by the LP.  LP filters can only do so much, despite the claims on their wavelength charts.  Even with NB some LP leaks into even very tight bandpass filters, even 3nm ones.

I always assumed LP filters would only improve my subs a bit. I can't imagine they can perform miracles. 

 

Cheers

[MKHACHFE]

15 hours ago, Budgie1 said:

The MW is very clear up here, more so on a crisp winter evening.

I live about a mile from Onich and far enough from Loch Linnhe to not be effected by the low cloud which forms on clear nights. I can see the LED street lights from Fort William if it's cloudy but there's no sign of them when it's clear. I recently got a ASI120MM Mini as a guide camera and connected it to a 9x50 finder, when I was imaging M51 a couple of weeks ago I could make out the centre of the galaxies on the PHD2 screen with a 2 second image update from the 120MM.

When are you coming back up?

Oh wow... amazing that you live so close to Onich. Lucky you.

To be honest, i could have imaged from darker but I like to be able to pop indoors when I want to. So I sacrifice a bit of dark skies and dark eye adaptation for comfort. 

I did notice some sky glow coming from the direction of Glencoe, which I initially thought might have been Glasgow, then realised that very unlikely. 

On out last night there we drove to the coast near Arisaig, clear skies and were blown away by the view just after sunset. I didn't have my camera, but we hung around till it was dark... and that sky was spectacular. Exceptionally dark location, even better than Onich. 

But also incredibly cold. Here is a photo we took. Stunning.

[MarsG76]

Yup.. amazing how much difference a dark sky makes to imaging and observing DSO.

 

[Budgie1]

7 hours ago, MKHACHFE said:

Oh wow... amazing that you live so close to Onich. Lucky you.

To be honest, i could have imaged from darker but I like to be able to pop indoors when I want to. So I sacrifice a bit of dark skies and dark eye adaptation for comfort. 

I did notice some sky glow coming from the direction of Glencoe, which I initially thought might have been Glasgow, then realised that very unlikely. 

On out last night there we drove to the coast near Arisaig, clear skies and were blown away by the view just after sunset. I didn't have my camera, but we hung around till it was dark... and that sky was spectacular. Exceptionally dark location, even better than Onich. 

But also incredibly cold. Here is a photo we took. Stunning.

I think the photo is looking at the Small Isles (Eigg & Rum) and they are Bortel 1, fantastic skies from out there! It's just that we're getting to that time of year when you may get stuck out there for a few days due to the weather stopping the ferry.

The sky glow is likely a combination of Ballachulish and Glencoe Village, but from where I am I can't see that as there's a hill in the way.

[MKHACHFE]

11 hours ago, Budgie1 said:

I think the photo is looking at the Small Isles (Eigg & Rum) and they are Bortel 1, fantastic skies from out there! It's just that we're getting to that time of year when you may get stuck out there for a few days due to the weather stopping the ferry.

The sky glow is likely a combination of Ballachulish and Glencoe Village, but from where I am I can't see that as there's a hill in the way.

I naturally assumed that the sky glow would be coming from somewhere much bigger than that. Of course,  in such dark spots, even small towns would provide enough sky glow to be visible.

 

Thanks for the info. I'll msg you on our next trip up...my wife and I will gladly buy you a beer or whisky. 

[Budgie1]

No problem, we can point you towards some of the lesser know places to visit.

Cracking sky out there tonight, NGC6888 is being imaged at the moment and I may keep going into the wee small hours as the seeing is really good. (Just thought I'd make you miss the place even more!!)