A not so dark sky

Posted on December 3, 2013 with tags photography.

I’m aware of how not-dark our modern city night sky is, but sometimes it still heavily surprises me how full of light it actually is.

Yesterday I went about five kilometres out of Zürich; I thought at that distance, on a reasonably dark hill, it would be good enough for some night-sky shots.

So I setup my tripod, only to realise I can’t expose over 30 seconds because (at low ISO and fast aperture, shooting not straight up), everything is bleached out:

First image - light pollution
First image - light pollution

I couldn’t believe my eyes. Yes, I heard that one needs to go 100Km out of big cities, but but… So I went and found that since about 2004, all of Switzerland is light polluted - even going on top of Jungfrau, for example, wouldn’t completely eliminate it. I also learned about Merle Walker’s equation - yeah, 200Km or more away from light sources would be good. Not here, in this quite small, quite populated country in the middle of Europe :/… I realised that as soon as my eyes got acclimated to the location I was at, I could easily see everything around me, due to the light pollution.

I miss a really dark sky - I remember a couple of years back, in a different country, stopping at night on the side of the road, and being shocked at how the sky was filled with starts. I didn’t have any camera with me at that time ☹ Heck, I remember seeing the Milky Way way back as a child, but nowadays when I get out of work, I can barely see 4-5 points of light in the sky.

Anyway, enough with ranting ☺ Thanks to modern technology, one can recover lots of detail, even in a washed out picture. So in the end, shooting straight up, I could get some resemblance of structure (and this was only at 28mm, which is not that wide):

First serious attempt
First serious attempt

Or alternatively, one can use the glowing light for a bit of play/contrast:

Contrast between the horizon and looking straight up
Contrast between the horizon and looking straight up

I also played with stacking images via Deep Sky Stacker, but stacking - I learned to my surprise - only works to reduce noise in the final image, and not to make it “brighter” or more detailed. Live and learn ☺ The result was a bit better than not stacked, but not by much:

Stacking results
Stacking results

This was a 25×5s, ISO 800, f/4, same 28mm lens. What I found surprising is the “non-star object” (to call it so) near the centre of the image - I have no idea what it is, it definitely doesn’t look like a star, it could be an elliptical galaxy or so. I tried navigating back in time via Stellarium, but I don’t remember the orientation of the lens, so it will remain a mystery to me.

Anyway, two more pictures and higher resolutions on a Smugmug album. Feel free to leave a comment or drop me an email if you have suggestions where to take nice night sky photos in Switzerland…