techniques

The beauty of photographing in low light conditions is the magical atmosphere that can result from the process. This river path looks quite uninspiring during the day but with a little light in the sky on a foggy morning it transforms into a fairytale image!

As the light changes there are an infinite number of possible photographs that can be taken. This is why low light photography is so appealing.

Night photography has its drawbacks. It pushes the camera to its limits, and methods that provide perfect results for daylight shots do not necessarily work when there is low light and in particular, artificial light sources. Problems such as viewfinder brightness, noise, long shutter speeds and lens flare are obstacles for the photographer.

The shooting techniques shown below are the ones that work for me. They try to simplify the process as much as possible, minimising the need to fiddle with camera settings in the dark.



equipment
Cameras: Canon 5DMkII, Canon 40D
Lenses: Canon 24-105mm f/4 IS L, Canon 24-70mm f/2.8 L, Canon 70-200 f/2.8 IS L, Sigma 17-70mm f/2.8-4.5, Tokina 12-24mm f/4 IF DX Pro
Tripods: Manfrotto 190PROB, Manfrotto 074 and Manfrotto 804RC2 pan and tilt head

setup
It is often dark before I leave, so I set up the camera before-hand with: 'manual' exposure, RAW files, ISO 100, auto white balance, auto exposure bracket, continuous shooting mode, 2 second timer delay and evaluative metering. If you have a custom function these settings can be programmed in.
I put the camera on a tripod before I go out and walk around with it over my shoulder. The RAW setting enables me to fix white balance later in the processing stage.

flare
To try and reduce lens flare with powerful street lamps I use some or all of the following techniques:
-Remove filters - extra glass causes more internal reflections
-Attach a lens hood
-Hide bright lights behind something in the composition
-Only use top quality lenses with special coatings
-Use a dark piece of paper to shield the lens from the bright light source - take care that you don't get it in the shot

noise
To minimise noise I try to shoot at ISO 100. It will lead to longer exposures but this should not be a problem on the tripod. Sometimes I will switch to ISO 200 if the exposure time runs over 30 seconds.

metering/exposure
Getting the exposure right can be very tricky with bright lights around. I like to try and shoot when there is some light in the sky. To me, photos of lamps and lanterns don't look as good when they contrast against a black night sky.
I've tried all kinds of metering methods to determine a useful exposure, including spot metering on buildings and using partial and centre weighted average methods with histogram help. Since low light histograms are nearly always low key I've settled on a simple technique which works quickly in the dark and involves gathering enough photographic information to sort out exposure during processing.
I let the camera make the decision using evaluative metering of shadows and bright light sources in the scene. By shooting RAW with several exposures there is enough headroom to adjust exposure later in Photoshop.
After composing the scene I adjust the aperture to give the desired effect in 'Manual' mode. Wide appertures gives a shallow depth of field and diffused lights. A narrow apperture gives a large depth of field and beautiful star shaped lights. However, the weather conditions can change this simplistic view. Here are two shots of the same lanterns on Welsh Bridge in Shrewsbury. They were both shot at f/13, one on a clear evening and the other when it was foggy.


I then adjust the exposure level indicator to the centre or zero position. Having switched on the Auto exposure bracket prior to leaving (usually at +/- 2 stops) I watch for the over and under exposure indicators. This process gives me my shutter speed. The Canon 5D MkII provides only 3 possible shots in auto exposure bracket but 1D series cameras and many Nikon DSLRs provide an option for 5 or 7 shots at different exposures. I would use those if I had the opportunity (having said that, I wouldn't swap my 5D MkII for all the tea in China)!
I'm afraid blown hightlights in the middle of bright street lamps often go with the territory!! It all depends on how much light is in the sky as to how much detail you can get in the lamps. Your darkest shot, however, will help you recover some highlights when processing later.
One final point, if my lightest exposure is more than 30 seconds then I use a remote self timer. Often though this is only needed for moonlight shots.

focusing
Auto focus doesn't work well in low light, although some lenses are better than others. I tend to use 'live view' then zoom in and adjust the focus manually. If it's not too dark and auto focus is working well then focus and recompose the shot as normal. I switch to the central focussing point only, it is more accurate and sensitive than the other points.

shooting
I will either use the 2 second timer delay or a remote to fire the shutter. Mirror lock-up isn't so important for long exposures but a good sturdy tripod is crucial. I try not to extend the central column too far, particularly if it's windy. After taking the shots I always check them out on the LCD display. With the flashing blown highlights set to 'on' it's easy to see how many problem areas there are on the darkest shot. Also check out the lightest shot and zoom into the shadow areas to see how dark they are. Experience tells me whether I need to reshoot either by over or under exposing the centre exposure level indicator.