Have you ever wondered how to get a night shot of the city with intense, fiery light trails? Well then read on my friends! This blog post is for those who want to learn how to shoot long exposure shots from the basics, as well as those of you who have already joined EYExplore's Tokyo By Night Photo Adventure and want to recap the settings and techniques you already learned.
In order to get into the deep end of long exposure night photography, let’s review the basics of a camera: shutter, aperture, and ISO.
The shutter setting allows you to control how long the shutter stays open, and therefore how much light comes into the camera. The secondary effect of the shutter time is motion blur. The longer the shutter, the more motion blur you can get.
The aperture is an iris inside the lens that controls how much light comes into the camera. We can make the aperture big (e.g. f/2.8) or small (e.g. f/16). The secondary effect of the aperture is its influence on the depth of field (DOF). For our purposes, all we need to know is that it gets deeper (more things are in focus) with a smaller aperture (e.g. f/11).
The ISO setting can be thought of as the ‘sensitivity’ of the camera’s sensor (or the film, if you’re using an analog camera). Essentially, the higher the ISO the more ‘sensitive’ the camera, which effectively means you’re getting ‘more’ light. In reality, a digital camera doesn’t quite work quite like this on a physical level, but for our purposes, this is a very convenient shorthand. The side-effect of the ISO is that the higher it goes the more noise or grain will be present in the resulting image.
Essentially, all three main functions (shutter speed, aperture value, and ISO) primarily affect how much light you end up with in the camera, while each of them also have a secondary effect.
How to set the camera…
With the basics out of the way, let’s move on to the settings we need for a typical night time long exposure shot in the city. Our goal is to keep our shutter open for as long as possible in order to allow the traffic to leave nice long trails of light in our photo. Let’s go with a typical shutter speed for this purpose: 4 seconds. This means the shutter stays open for 4 seconds to capture light, which is quite a long time. If we do not consider our other 2 settings carefully, then we will be left with an overexposed photo. In most shots on our photo adventure in Tokyo, this means we need to make the aperture smaller and reduce the ISO.
A good aperture setting for this shot could be f/11 (remember—a bigger aperture number means a smaller aperture). At this aperture, we have reduced the amount of light coming into the camera considerably. The secondary effect is that we also have a wide Depth of Field, meaning more things are in focus. This is perfect for a cityscape shot.
Next, we need to consider our ISO setting. We are trying to compensate for the large amount of light coming in during our 4 second exposure, so we need to keep the ISO quite low. Most cameras these days can do 100 ISO at the lowest. Going with the lowest ISO also has the added benefit of reducing noise / grain in the photo.
So, let’s recap the settings for a typical night long exposure photo: 4 second shutter, aperture f/11, and ISO 100. And that’s it! From there you might adjust the aperture a bit (say between f/8 and f/16) and work on the shutter time, anywhere from 1 second to 15 seconds depending on how much light is in the scene.
This covers the very basics of an urban long exposure photography, just like the ones we do at EYExplore on our Tokyo By Night Photo Adventure. I did gloss over a few details, so in the future, I’ll go into more depth and cover some advance techniques.