Long Exposure Photography

Long Exposure Photography – Painting With Light

In my ‘balancing light’ article, I mentioned that in long exposure photography, slowing down your shutter speed will create motion blur in fast-moving objects, even at the fairly high shutter speeds that a bright and sunny day will allow you to use. This is the primary reason why nighttime photography is such a challenging (and frequently bungled) endeavour; there is so little ambient light available that you are forced to use slower and slower shutter speeds and the motion blur becomes more and more pronounced, to the point where the object itself is basically invisible.

This could theoretically be quite a big problem, obviously, but can actually be worked to your advantage to create very striking artistic images. You can ‘paint’ with light by using what little ambient light is available, as well as some strategic additions of your own, to make works of remarkable surrealism, proving that the old saying about the camera never lying is, in fact, a complete lie in itself. The best known of these techniques – and the easiest to recreate in Bangkok – is the light trails from traffic.

Long Exposure Photography – The Technical Stuff

The picture you are trying to create, in this case, is quite a popular one from TV and movies. Whenever they want to show a lot of time passing in a city environment, you see the moon streaking across the sky, building lights flickering on and off, and vehicle headlights streaming along the main roads so quickly that they look like unbroken beams of colour, floating just above the tarmac.

Fortunately, you don’t need all night and a ton of film equipment to take such a striking picture. You need a DSLR, a solid perch and a good angle. A bit of patience is always helpful and a high-capacity memory card certainly wouldn’t go amiss, too. Lens-wise, something wide would be best – a 10-20mm wide-angle lens or just the lowest focal length on an 18-50mm kit lens.

In this case, the most important technical requirement is actually the solid perch. A sturdy tripod is always best because they give you the full freedom to move the camera around exactly as you please and direct the lens more precisely. Good tripods are heavy (and expensive), though, and I can’t deny that I’ve shied away from lugging mine around in favour of just finding a convenient railing more than once.

Long Exposure Photography – Motion Blur

As we know, motion blur is created because the sensor is trying to capture everything while the shutter is open, but certain objects continue to move and it is impossible for the camera to capture every single detail of an object that is not in the same place from one instant to the next. This is especially true if the target is quite dark, such as with the body of a car travelling at night.

The sensor works on light – that’s the whole point of photography (‘photo’ means ‘light’). If an object is bright, such as the same vehicle’s head- or tail lights, that will be captured in detail, even if the object creating the light is not. That is why you get the ghostly trails along seemingly deserted roads. The road and buildings will be captured because they are not moving, so the sensor has enough time to absorb enough light reflected off them to form a clear image.

So long as you have your stable platform, the entire trick to this shot is lowering your shutter speed. Going slower and slower will create longer light trails and increase the motion blur of the cars themselves to the point that they disappear entirely. However, slowing the shutter increases the overall amount of light hitting the sensor, which risks over-exposing the shot.

You will need to reduce your ISO and raise your aperture to compensate. A 30-second exposure would probably be long enough (you’d be surprised at how long that really is!), particularly if it is quite a busy road. All that jargon, as well as the knock-on effects that altering these settings will have, was explained in a previous article, but is better learnt through a photography course in Bangkok if you want to really understand it properly.

Choose Your Road

The actual art of photography comes from choosing the angle. Fiddling with settings is just the mechanics of it – the same as a painter mixing their colours and selecting their canvas. Fortunately, Bangkok has tons of great angles to choose from.

You have three basic options of where to look, each with their own advantages and disadvantages. In all three cases, you want to try to find a road where the flow of traffic is pretty regular and consistent. Practically deserted roads (with only a few vehicles), have their artistic merits, but gridlock is completely worthless.

Long Exposure Photography – Street level

Naturally the easiest to get to and you have the widest selection of roads and potential angles on those roads. You get the quite cool effect of the light beam streaming right by the camera, with its distance above the tarmac made more obvious. This does limit the scope of the shot, though. You also have far more chance of the camera being jostled, creating camera wobble and ruining the shot, not to mention the risk of people walking or standing in front of your lens at a critical moment.

Long Exposure Photography – BTS level

It need not necessarily be a BTS station or walkway; footbridges and second or third storey balconies would work just as well. With all of the potential perches on the BTS lines, you still have a lot of choices for roads and angles, with much less chance of being blocked or disrupted. You also get a wider shot over the whole road, meaning more light trails and more background. The trails look most striking if you can see more of the city they are passing through.

Long Exposure Photography – Rooftop level

Bangkok has plenty of bars and clubs on the 20th or 30th floors of high-rise buildings, and they’re probably used to photographers at most of them. Naturally, you get less choice of angles, but you do capture much more background and many more lights. In my opinion, though, this is too far away. The trails become indistinct – just lines in the night, instead of ghostly lights floating along deserted streets.