Becoming Familiar with Long Exposures

Tech

How to perfect the long exposure

Technically, long exposure is a fairly straightforward process when it comes to photography. Alongside Clifton Cameras, a specialist in all things cameras, we help you get the best long exposure shot. Before you’ve even started you’ll need a tripod; this is because when you’re working with a slower shutter speed, the camera will detect your movement if you shake your hand. By pressing the shutter with your finger, this may produce enough vibration to disrupt the image within the frame, so we would advise that you set your camera to a two second timer, or that you use a shutter release to ensure you’re capturing the perfect long exposure photograph.

When capturing this type of image, your camera’s settings a very important. Setting your shutter speed is a key aspect of this type of shot, so be sure to use the shutter priority mode or opt for full manual mode if you want to be completely in control of the exposure.

As you’ll probably be looking to take one of these images at night, in order to capture trailing light, focus can be more difficult to capture within the frame in dark settings, as the autofocus feature on a camera struggles with less light. However, using artificial lighting methods such as a torch may help in capturing the subject or object you’re photographing. We would recommend that in these instances, that you should use the manual focus option; in this way, you’re able to use the camera’s live view mode through the LCD as an aid in darker conditions. Make sure that you take plenty of test shots, and make sure the camera’s focus ring remains steady and doesn’t move – a good way to do this is to use duct tape.

If you’re not shooting at night, and you’re shot is going to be in daylight hours, then you’ll more than likely need to use a ND – known as a neutral density filter. This filter blocks out natural light, and this allows the shutter to open for longer when exposed to high levels of light. Each time a filter is applied, it is known as a ‘stop’, and these stops increase by factors of two, which can be best demonstrated like this:

  • 1 stop = 21 = 2 = ND2
  • 2 stops = 22 = 2 x 2 = 4 = ND4
  • 3 stops = 23 = 2 x 2 x 2 = 8 = ND8
  • 4 stops = 24 = 2 x 2 x 2 x 2 = 16 = ND16
  • 10 stops = 210 = 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 = 1024 = ND1024

As explained, a ND filter allows you to limit the amount of light that is being exposed to the lens, and ND10 reduces light by 1024x. Reducing levels of lights can help long exposure shots during daylight hours, but you’ll need to take a while adjusting the frame to accommodate for the loss of light. Some cameras have a small shutter that closes the viewfinder when ND filters are on, but others don’t, if yours is the former then you’ll need to use other methods such as tape to make sure that no light enters it.

Setting your exposure

To take a quality long exposure shot during the day or night, you’ll need to establish what length of exposure that you require before you begin; we’ve put together some general rules that you should follow:

Daylight exposures – As we’ve explained, shutter speed in these instances is dictated by the ND filter you use. When using an unfiltered exposure of 1/15 sec, a 10 stop ND exposure should last 1 minute. Whereas a 1/8 second exposure should be 2 minutes, a 1/4 second exposure should be 4 minutes, and a 1/2 should last 8 minutes. Your ISO should be set to as low as possible, around 100 or 200 at most.

Night exposures – During a night scene, shutter speed should be set at about 10 seconds. As well as this, use an aperture of around f/5 to f/11, but this will vary depending on the scene. Remember, ND filters aren’t necessary in the dark, and your ISO should be no higher than 500.

  • What’s important to note at this point, is that some cameras include a bulb mode. This mode allows you to keep the shutter open for as long as possible, and without this mode, some cameras only allow you to keep the shutter open for 30 seconds. This feature is particularly useful when taking photographs of water in the dark, as the lengthened exposure allows you to capture any detail.

After becoming familiar with all of these different methods, it’s down to you and practicing. Once you’ve got your tripod, and understand manual focus and exposure – you can go out there and start capturing great images every time; here are a few suggestions just to get you started.

City lights at night. You’ll have definitely seen these types of photographs before, and lights can often wind through sweeping valleys and hills. Or, you can capture the city at night and trail the lights of cars; for the best image, set your shutter speed to 10 to 15 seconds.

Drawing with light. With the aid of a long exposure, you can draw or effectively paint with light. This is because long exposure times capture light in the same position after you have moved a torch or a laser pen for example. These images can be incredibly atmospheric so be as creative as you like.

Framing coastal landscapes. Images of the sea and the horizon are best captured at dusk or dawn, which helps to draw the most romantic elements of the frame.