Saturday, March 02, 2013

Dark Skies in Galloway

Low-light photography comes with its own particular set of challenges, night time photography even more so. So when I decided I was going to have a go at photographing the stars, I knew it wasn’t going to be easy.

Large parts of the world are so full of light pollution, at night you can barely see the brightest stars, even on the clearest of evenings. However, there are parts of this corner of Scotland which have achieved “Dark Skies” status – where you have the chance of seeing far more of the thousands of stars potentially visible by the naked eye.

Last week I drove up into the hills above Gatehouse, camera, tripod and wide-angle lens at the ready.

Unfortunately, photos of the stars on their own just aren’t that interesting (as always, feel free to click on any of the images for larger versions).


Recognisable stars, but with no real reference point

If you know what you’re looking for, you can see Orion’s belt (the 3 stars in a row in the bottom 1/3 of the left of the photo), and if you follow the line of it you can also make out Jupiter (the bright star), and the Seven Sisters (small clump that looks like a tiny saucepan). But you need a telescope attached to your camera be able to take amazing photos of something like the Horsehead Nebula.

So the reason for a wide-angle lens is to get in some of the landscape – this helps to give the stars a context. Rather than being a random set of white dots on a dark background, we can see it is a night sky and immediately imagine we are the ones standing there in the silence, with the cold air on our skins and the smell of heather and bracken in our nostrils.


Orion and Jupiter above Gatehouse of Fleet

However, the moon was out and that started to cause light pollution of its own, making the number of stars visible, much fewer. So I decided I’d try again the following night, before the moon rose.

The next evening I headed into the Galloway Forest to Clatteringshaws Loch, figuring that water and stars might make a good combination. And it was, breathtakingly beautiful – far more than I know how to capture with a camera – after all, portraits are my speciality, not landscapes.

But the biggest problem faced with taking photos by starlight is, that in order to let as much light into the camera as possible, you have to have the shutter open for a much longer time. Normal, daytime photos, are taken with shutter speeds like 1/250th of a second, but those photos above required a 30 second exposure.

And once you start getting to those times, the problem is the rotation of the Earth starts to interfere with the photography. From the time you open the shutter to the time it closes, the stars have moved, relative to us – so instead of being sharp dots, they create trails.

So if you look at the two images below. In the first, the shutter has been open for 57 seconds, and the trail effect is just starting to happen (exaggerated further at the sides of the image because of the effects of a wide-angle lens).

In the second, the shutter has been open for over 3½ minutes, but although this allows for far more of the stars to show, the star-trail effect becomes far more noticeable. It also means the orange glow of light pollution from small villages in the distance becomes more prominent – a glow usually so faint you don’t see with the naked eye.


Clatteringshaws Loch - 57 second exposure


Clatteringshaws Loch - 3½ minute exposure

Eventually, after trying various combinations, the moon rose and started to create too much light pollution again. So I decided to drive round to the side of the loch and see if I could get a shot of it reflecting on the loch, and this was the result.


Moon over Clatteringshaws Loch

Do you live in place where you can see the stars clearly at night?

9 comments:

mapstew said...

We're right on the edge of town, just two minutes from open countryside, so meself and a pal had a clear view of the stars the other night. (Along with an open fire and some beers!)

The weather is perfect for star-gazing. Great shots Kim. :¬)

Baz said...

I've had a go at the night sky stuff myself hardest problem I found was trying to focus on infinity in the pitch black.

hope said...

The joy of living in the country...next to no "invasive" light from cities. Occasionally a farm has the lights on during harvest at their grain silos but otherwise, I was shocked at how many stars we could see when we moved out here.

Eryl said...

I rather like the light trails, and would never in a million years have thought that they were caused by the earth moving.

Pat said...

Yes!
Next time you come let's go up on Exmmoor.

Those are so lovely and the moonlight one makes me go all gooey.

Kim Ayres said...

Mapstew - Sounds great :)

Baz - ah, yes, now that is damn tricky. On the first night when the moon was out, I used the autofocus on the moon, then switched over to manual and didn't touch it again. On the 2nd night I was hoping I didn't accidentally knock the focus ring. However, with the wide-angle lens there's more flexibility anyway as the DOF is much deeper anyway.
With my zoom lens (70-200mm), at full zoom, Jupiter is bright enough for it to autofocus on it, and then, once again I switch it to manual and don't touch the focus again.

Hope - it's reckoned that if there's no light polution, on a really clear night you can make out two to three thousand stars with the naked eye.

Eryl - some photographers use the star trail effect as a feature of their images. Take a look at these:
http://1x.com/photo/25132
http://1x.com/photo/42045

Pat - that sounds lovely - we'll definitely have to do it :)

Guyana-Gyal said...

I saw a documentary on tv about this problem, light pollution.

One night, a couple of weeks ago, I stood on the road just outside our driveway and watched the stars. I could've stayed there all night, enjoying the sea breeze and the stars.

But the best I've ever seen the stars were in some small towns in Australia. I saw so many falling stars.

allencapoferri said...

That's beautiful. You may find it hard to imagine but I've not been awake late enough to know if the stars are as visible. I've really become the "early to bed guy" in my autumn years.

Kim Ayres said...

Guyana-Gyal - I imagine Australia would be a great place for star gazing. I found this map of the earth at night which shows which parts of the world have less or more light polution:
http://apod.nasa.gov/apod/image/0011/earthlights2_dmsp_big.jpg

Allen - how about early mornings?