Tips

Reduce your shutter speed

In some cases, you may need to reduce the shutter speed anywhere from one second, to a few minutes in order to get the correct exposure. If your required exposure  is more than 30 seconds, you will need to change your cameras settings to Bulb Mode (b). Shooting at slower shutter speeds may require the use of a tripod. The stability of a sturdy tripod will provide you with the sharpest possible image.

Helpful hint:
When trying to figure out the minimum shutter speed for going ‘hand-held’, a great rule of thumb is:

Shutter speed = 1/(focal length x crap factor of sensor)

For example, I am using a 5D Mk2 (crop factor of 1.0) with a 50mm lens. This would mean:

1/50 = 1/ (50mm x 1.0)

A shutter speed of 1/50 would be the slowest I would use ‘hand-held’.

Open up your aperture

Another method of increasing your exposure at night is to open up your aperture (eg: from f/8, to f/2.8). You can let in twice the amount of light, just by increasing your aperture by 1 full stop.One benefit of opening up your aperture, would be if you wanted to keep you shutter speed at a rate that would be acceptable for ‘hand-held’. Just keep into consideration that opening up your aperture, gives you a shallower ‘depth of field’.

Increase your ISO

Increasing your camera sensor’s sensitivity can be a great trade off against opening your aperture and reducing your shutter speed, but can have a big disadvantage to allot of cameras… noise. The more you increase you cameras ISO, the more it becomes sensitive to light, but that includes noise.

The key to getting the quality image with these three tips is knowing which trade-offs to make. Your shutter speed will affect the ‘motion blur’ & ‘camera shake’, but could also be used in your image to capture movement in an object (the ocean, or a vehicle). Your aperture will affect the ‘depth of field’, but could be used to draw the viewers attention to the subject in the image. And your ISO will affect the noise in your image, so try to use the lowest possible ISO to achieve the correct exposure.

Techniques

Photographing Star trails

One advantage of taking long exposures at night, is capturing images of star trails. The trails are created as the earth rotates, giving the impression of the stars moving across the sky. To photograph star trails, all you need is a camera that remains fixed to a sturdy tripod and a cable release. With your exposures, you’ll be taking images with an exposure time of several minutes up to several hours, depending on how moonlit the night is, so you’ll need to set your camera to ‘b’ or ‘bulb’ mode.

Night Photography by Moonlight

Just as how daylight photographers pay attention to the position and angle of the sun, night photographers should also pay careful attention to the moon. A low-laying moon can create long shadows on cross-lit objects, whereas an overhead moon creates harsher, downward shadows.

An additional variable is that the moon can have varying degrees of intensity, depending where it is during its 29.5 day cycle of waxing and waning. A full moon can be a savior for reducing the required exposure time and allowing for extended depth of field, while a moonless night greatly increases star visibility. Furthermore, the intensity of the moon can be chosen at a time which provides the ideal balance between artificial light (streetlamps) and moonlight.

Night Photography Using Flash Units

The long exposure multiple flash technique is a method of low light or night  photography which use a mobile flash-unit to expose various parts of a subject.

This technique is often combined with using coloured gels in front of the flash-unit to provide different colours in order to illuminate the subject in different ways. It is also common to flash the unit several times during the exposure while swapping the colours of the gels around to mix colours on the final photo. This requires some skill and a lot of imagination since it is not possible to see how the effects will turn out until the exposure is complete. By using this technique, the photographer can illuminate specific parts of the subject in different colours creating shadows in ways which would not normally be possible.

Night Photography Using Torches

When the correct equipment is used such as a tripod and shutter release cable, the photographer can use long exposures to photograph images of light. For example, when photographing a subject try switching the exposure to manual and selecting the bulb setting on the camera. Once this is achieved trip the shutter and photograph your subject moving a flashlight or any small light in various patterns. Experiment with this outcome to produce artistic results. Multiple attempts are usually needed to produce a desired result.

Metering at Night

One way of metering in low-light, is to first meter using a larger aperture (like f/1.0, or f/1.4), so you can keep your metered exposure time is under 30 seconds (and in manual mode), then stop down as necessary and multiply the exposure time accordingly. Alternatively, you could use this table to make life a little easier. This chart shows you 11 different combinations of shutter speed + aperture that will provide you the same exposure for each EV level.

Examples