Steve Arnold Photography

I’ve been fascinated with the universe and the night sky for a number of years but I suppose only passively, until a couple of months ago when I watched a number of documentaries back to back that really ignited that fascination, converting it into a what might be described as an obsession! So I started researching the milky way and the best times to view it, the types of photograph that can be made of it and where, locally I might be able to try to make a picture of it.

Here’s what I learned before taking my first shot:

The first point is an obvious one, but very dark and clear nights are better for stargazing.
The darkest nights occur when the moon is around a “new moon” phase which is when it is least visible (i.e. a tiny slither, or completely dark).
It’s best to be as far away from urban light pollution as possible.

Where I live, on the southern edge of Sydney, is ideal for getting away from the city lights and it’s just a short 10 minute drive into the Royal National Park rainforest. Last Thursday was a really clear evening and the moon wasn’t due to rise for another few hours so I packed up and headed down into the rainforest.

Here is my first ever shot of the milky way, that I took that night:

Here’s I learned from this first nights’ shoot:

You can get a decent shot of the milky way following some basic methods. These are; shoot at your lenses maximum aperture; shoot at a higher ISO than you might think normal; a 30 second exposure is about as long as you can make it without the stars showing movement in the sky (from the rotation of the earth).

Your camera can “see” more than your eye if you let it expose for long enough. What i mean by that is whilst I could make out the shape and position of the milky way in the sky with my own eyes at the time, the camera is picking up a lot more light over that 30 second exposure and so “sees” it much more vividly.

I was pretty happy with my first attempt and it gave me some confidence that I could take with me when Sonia and I were to go camping in Kangaroo Valley at the weekend.

Kangaroo Valley

About two hours drive south of Sydney is a beautiful area known as Kangaroo Valley. We headed down on Saturday knowing that should the clouds stay away we would have perfect conditions for shooting the milky way. We pitched our tent at a free camp site about 8km’s from the nearest village and when night fell we realised how lucky we were to have the clearest, darkest skies that I ever remember seeing. The milky way was right overhead, stretching across the entire sky from the south to the north. As impatient as I am, I wanted to make the most of it as soon as possible so I started shooting the tent with the night sky behind it. After a couple of shots I asked sonia to stand off to one side and illuminate the foreground with her headlamp, she duly obliged and the result was this next picture:

After some messing around outside the tent a sudden waft of mist engulfed the whole area so we quickly packed up and headed off to the spot we had earlier scouted for some star trail photographs.

In the end we had about half an hour of shooting left before the mist and clouds closed us off from our view, in which time I had managed to grab enough shots to make the following composite star-trail image:

The idea with a shot like this, is that if your camera exposes for long enough it will capture the movement of the stars in the sky as the earth spins on its axis. My prior research also led me to look for the “Southern Cross” which is the southern hemisphere’s equivalent of the North Star, which is the point in the sky that stays still whilst the rest spins around it. A great little iPhone app named Star Walk helped me locate this central point by overlaying a labelled rendering of the sky on my screen as I moved the phone around in front of me.

The catch with the method I used for this shot is that although the result is a 30 minute exposure, it was not truly a one-shot exposure. By taking 60 continuous 30-second exposures (turning OFF the noise reduction in camera so as to not have to wait 30 seconds between shots) and then combining them into one with a handy little program called StarStax, you can achieve the same effect.

The stacking of multiple exposures is a lot less risky in terms of things that can go wrong when compared to a single loooong exposure. For example, a few planes flew across my shot creating out-of-place light trails that streaked across my picture. But because they only showed up on one or two individual frames I was able to just exclude them from the final piece. (The downside of this is that if you cut too many shots out you will get gaps in your star trails – as what actually happened here, but I was happy to take the hit on that over having the planes ruin the whole shot). If I was doing this in just one single exposure, there would have been a good chance that the planes would have shown on my final image and I would be stuck with them! I did leave one section of plane-trail in the shot, notice the yellow line just behind the trees and then imaging three of those streaking across my entire photo at various angles…

Other points to note about this shot, and this technique in general;

The closer the stars are to the point of rotation, the shorter their trail will be.

Clouds started coming into the shot for the second 15 minutes which although did not ruin the image completely, it did break up the star trails quite a bit – notice the dotted lines towards the right side of the photo.

With noise reduction turned off and high ISO’s being used (in my case 6400 on my 5dMk2), having a fast lens would really help. My 24-105 lens only goes as wide as F4, if I were using an F1.8 i could have dropped the ISO to a much more friendly value like 800-1600… Or just kept the high ISO and made those stars REALLY shine. But really this is the first time I’ve felt like I was pushing the limits of my equipment. The noise in the image really is very high and although Lightroom does a good job of fixing it, I’d rather get a clean shot to begin with. I really need to consider a fast, wide angle lens as my next investment.

When choosing between the two techniques (multiple stacked shots vs one long exposure), the kicker for me is that you can get double value from the multiple shot method – you can sequence them into a time lapse video! Although half an hour of shots only gave me enough for two seconds of video (so is not worth posting here) it was enough for me to see the milky way drifting across the sky in front of me!

Well, i’m not sure if this blog post is well structured, makes sense, or is news to anyone – I’ve just been performing a bit of a brain dump – but hopefully you will at least enjoy the photos

And before you go, please take a look at this link – Sonia has uploaded some VERY cute shots of some wombats that were wandering around our camp site in Kangaroo Valley

See you next time

Steve