Story of... Out After Midnight

Posted as an insight to this image on flickr of a long exposure star trail over a small island.

The changes were tiny at first, and I barely noticed them.

But soon the patches of darkness caused by increasing distances between streetlights meant there were places for people to hide. I stopped beneath a lamp to question whether I was doing the right thing, out after midnight in a town I don't know in a country whose language I don't speak.

On the one hand I was tired, having walked many km over the last 24 hrs looking for potential locations; my legs were starting to whisper that they didn't have much left in them.

On the other hand, I hadn't seen a soul since I left the hotel so what were the chances of needing to flee from an aggressive stranger?

Turning Point: where the houses started to change (© Google)

I looked to where I'd come from. And turned back to face where I'd been heading. Behind me, small houses, low apartment blocks, taller towers of flats and the distant glow of the city. Ahead of me small houses, bigger houses, bigger houses with more land. The cars got newer and shinier.

It wasn't until I saw a small dinghy in someone's front garden that I knew my hunch was going to pay off. Looking out over water from this near-island city would mean looking towards nothing but clear dark skies. Shuffling my camera over my shoulder felt reassuring, serving as a reminder how I'd found myself in this moment.

I walked on.

Just a few hundred metres further I found the lake and spent a few minutes watching the settled mist on the water. One of the most common disruptions to night photography is a lens that won't stop misting over. Would it happen to me? Hopefully the time spent with gear over my shoulder had allowed it to adjust to the ambient temperature.

Nearly... couldn't make a landscape version work

To the right of the island, Orion had just risen above the waterlogged horizon. With its 7 bright stars, Orion would have left a landscape frame too imbalanced so I set up vertically, taking extra time in the extreme darkness to align the horizon precisely.

When I'm out on location, one of the ways I double-check my alignments is to fire off a test shot then zoom in to a horizontal or vertical line within the frame to see if it runs parallel to the margins of the camera's preview screen. Unable to make out any usable reference points, it took several attempts on this occasion.

Having gone to the expense of hiring a fast, wide lens, I wanted to shoot at f/1.4 so that was the first setting to get dialled in. My ISO started at 200 which is the native setting on the D300- the point at which its most comfortable; the point with the most dynamic range.

Next up, 30sec on the exposure duration. It's the longest most cameras will expose for without manual intervention which makes it ideal for star trails where you want to fire off dozens of frames continuously with the cable release locked down.

I shot a frame at those settings and reviewed: the stars were coming through just fine but the scene was darker than I liked. I added light with exposure adjustments and a minor ISO shift then set the shutter running.

Couple of little tips for you: an intervalometer would have made things so much easier than standing next to the camera throughout the exposure, clicking the shutter cable closed then open again at a precise frequency. Without the intervalometer I ran the risk of missing an interval, or knocking the tripod, or some other element of human error. As it was, the timer on my phone alerted me to each passing minute and, fortunately, things turned out good.

Secondly, standing in the dark my camera becomes the brightest object around when I preview my shots. The LCD brightness is turned down to compensate but I always add up to 2/3rds stop of light to what looks like the right settings, just to be sure.

Starting to feel the cold of the Finnish autumn and aching from shutter RSI, it was time to pack up, but not yet time to let my guard down. With the reverse walk ahead of me I pocketed the memory card, a habit to safeguard my work, and headed back to the hotel.

Route: Thankfully I travelled light for the walk (© Google)

At home, I'd have fired up the MacBook straight away to start with the process of stacking. A room full of family told me that was a bad idea so the PP waited till morning.

For a single frame of pinprick stars an optimised image requires more extensive PP. But with startrails filling the sky so comprehensively, the effort invested in setting up the camera on-location means a light-handed approach to PP is fine. Camera JPGs were stacked in StarStaX before being imported to PS for minor tweaks to WB, contrast and saturation.

I guess the changes are tiny, and you'd barely notice them.

How to... top tips for urban star trail success

For years I'd heard people say urban star trails couldn't be done: the ambient light's too great; you need to get far away from any light pollution; everything turns orange. Stand in the middle of a city on a clear night and you'd be forgiven for believing it. From down amongst the garish glow of streetlamps and neon signs promoting food you'd never eat when sober it's near-impossible for our eyes to pick out pinpricks of starlight high above.

For our cameras, though, it's a different story altogether. f/2.8 is f/2.8, wherever you happen to be pointing your lens- as far as environmental awareness is concerned, the camera is pretty dumb. So I figured it was worth searching out a composition to disprove the theory and see what happens when you shoot urban long exposures at wide apertures.

There's one thing in particular that continues to fascinate me about capturing urban star trails and that's how the result can appear to flip reality. You might expect to see a human element in some frames but at ground level there's just stillness. Instead, what you don't expect is how the sky's brought to life by the earth's perpetual motion.

So that's my take. Whatever your motivation, the complexity of shooting urban star trails means the results can be very rewarding. Before you get out there and try it for yourself here's a handful of tips to point you in the right direction.

Ditch the wide angle and look up.
You need to get above the level of the streetlamps. Most of the time that's not physically possible so let a longer lens do the job for you - my 35mm and 50mm primes have seen lots of use for this reason. Avoid areas in direct street lighting, which usually means compose your camera upwards, but try to find an angle that captures an ambient glow to shed a little light on your foreground.

Shoot wide open.
Stars don't disappear from view just 'cos you're at an urban vantage point, they simply become harder to see with the naked eye due to the contrast between dark sky and ambient streetlighting. If you can find a composition that lets you shoot long exposures at f/2.8, the stars will be there. Use exposure duration to control the ambient light - how bright the scene looks is down to personal preference but I tend to use 15-30 second exposures and run consecutive frames for 20-60 minutes.

Learn your hyperfocal distances.
You might think shooting a scene at f/2.8 would give you depth of field headaches but there's a factor of DoF that often gets forgotten. Sure, it's about focal length and aperture but the final piece of the triangle is focal distance - how far away you are from your subject. Hyperfocal distance gives you the data you need to find a winning composition with your lens wide open. Get the data you need at DoFmaster

Get orientated.
If you want circular trails, find Polaris (the pole star) by running an imaginary line from the end of the scoop of The Plough constellation. A good starting point is to face north and look up. For straighter trails, shoot south or a few degrees either side. In the same way the rim of a bike wheel covers more distance than the hub in the same time, pointing your camera at Polaris means a long wait for extended star trails, whilst shooting away from the pole star makes your trails seem to grow at a quicker pace.

Set up the camera right
If you're shooting RAW you can skim this bit as you'll make your adjustments in PP. I tend to shoot JPG - stacking using StarStaX freeware is so much quicker than using PhotoShop so it matters how the camera's set up.

> White balance: neutralise the orange colour cast from streetlamps by manually setting your WB all the way down to 2500K. This adds blue back into the image.

> Contrast: max it right up to cut through the city haze that often appears around well lit areas.

> Brightness: your pic's going to be pretty bright anyway, you can probably keep this at zero.

> Saturation: adding saturation also adds contrast so a little can be a good thing. If you can't shift the urban colour cast with manual WB, though, the option's there to turn down the saturation- or you could convert to mono in post. Shooting star trails using mono in-camera is an unreliable method as often the toning can eliminate subtle star trails that would be captured in colour and could be retained by subsequent careful conversion to mono.

Know when to give up
Not every excursion ends with a successful image. If your efforts are coming to nothing because of location, weather, streetlighting or some idiot trying to jump in front of your camera (I've packed up on occasions because of each of these), it might just be a sign to take an early bath.

There's always the chance you'll reflect on what you did manage to capture and appreciate it for other reasons. The shot above got clouded out after just a few minutes but I've reached the conclusion that trails any longer would have over-complicated the image.

If reading this has left you inspired to get out and try it for yourself I'd love to see what you come up with. Feel free to outlink to your work in the comments below.

Story of... "Time"

Shooting solo so often, I tend to do a bit of research before embarking on any expeditions outside my home town. With flickr and google maps you can get a pretty good feel for things like parking, access and vantage points. Having scouted this location virtually I made the journey for real for the first time back in February, only to encounter hostile conditions on arrival. Six weeks later I struck lucky on the second attempt.

Each attempt involved a 160 mile round trip taking 4 hours in the car. It's a fair old trek down to the beach from the road (and moreso back up again!) and so eerie were the grazing sheep I could hear but not see I decided to count my footsteps to distract my mind. About 2200 each way, with nearly 2000 more paced up and down the beach whilst the exposure was burning. It was cold down there so keeping moving was a priority, especially as the need to carry tripod and peli case on the walk down meant my fingers were already pretty chilled through. And, in the excitement of the moment (c'mon, simple things keep me happy) I'd not considered the effect on the beach of the outgoing tide so knelt down to assess the perspective through the arch thus soaking my jeans from the damp sand

Before I set out to create this image I'd looked around to see if it had been done before. It hasn't that I can see, and I'm pretty sure the challenges of the location play a part in why not, despite the high rewards. On the journey down I had it in mind to stack, a layering technique that allows you to capture star trails even in areas with ambient light. As it happens, these were pretty much the darkest conditions I've ever encountered whilst shooting outside and my test shots at ISO1600 then ISO3200 served no purpose other than to confirm the darkness. It was even too dark to assess the composition through the viewfinder so this framing was achieved by numerous test shots at ISO6400 to manipulate the horizon and positioning of the arch.

As it turns out, stacking wasn't necessary. I knew from the equivalent metering of my high-ISO tests that at ISO200 the exposure duration would be sufficient to achieve a visually strong arc of stars through the sky. 1568 seconds when the shutter closed; or just over 26 minutes. When I got back to the car it was nearly 2am. The thermometer on the dash was reading -1.5ºc. At this point I should probably mention my fractured coccyx, picked up from an uncomfortable landing a couple of weeks previously and doing all kinds of wrong to my pain receptors as I sat in the driver's seat. I necked a couple of painkillers, turned the ignition and let the euphoria of seeing my camera's preview screen glide me home.