How to use a flash to take great low light photos
The arguments for and against flashing
Flash photography can rouse many long winded arguments. There are those heavily against it and never use it (such as Henri Cartier-Bresson), those who are masters of multi, off-camera flashes and those who have deliberately exploited it’s limitations to create an aesthetic in its own right (like Terry Richardson). With respect to low light photography, one could quite reasonably argue that it is the exact antithesis of the genre! However, there are occasions when it can be used to enormously enhance the image you’re aiming to capture.
An on-camera flash will typically fire at a specific shutter speed and this automatic setting of the flash does a number of things: It freezes the action. It creates a very distinct shadow. It leaves significant dark areas. And, it produces very ‘unnatural’ imagery. None of which sounds very appetizing. So how do we get around these problems?
Slow Synchronisation Flash
One trick to using flash is to exploit what is known as ‘slow sync flash.’ (Sometimes marked as ‘Night Mode’ or ‘Party Mode’ on smaller cameras).
A flash would typically fire at 1/60th second (allowing the shutter to fully open). This is what gives the frozen in time look. However, you can fire the flash at much slower shutter speeds too. This means the shutter opens, the flash fires, but the shutter remains open taking in some of the ambient lighting. The slower shutter speed and flash combination freezes the most static areas but makes other movements blurred.
To this long exposure/flash combination can then even be added an extra dimension. Whilst the shutter is still open, try winding the zoom lens back in or further out. (This only works if you’re using a DSLR with a zoom). This technique can result in some dizzying images with double exposures, movement and changes in colour and scale.
Off Camera Flash
One of the best ways to remove the ‘nasty’ effects of a standard flash is to move the flash off the camera. This will create all sorts of dramatic chiaroscuro whilst also eliminating some of the less desirable effects that on-camera flash causes.
To move the flash off the camera you will need a few pieces of kit. Off-camera flash can be done remotely with a variety of flash triggers (which vary from the affordable to the extortionate) or with cables. Remote triggers work in different ways and the cheaper ones may depend on a direct line of sight from the camera to the flash. They will also have shorter working distances. More expensive models will work in a wider variety of situations and have a greater range of controls. Cables, obviously, will only stretch so far!
Rear Curtain Sync
If you take a slow sync flash photograph at night of a moving car or bicycle something will immediately become apparent. The light trails from the moving subject go the wrong way!
This is because the flash has fired when the shutter opens and then the subject is still moving after the flash has stopped but with shutter curtain is still open. In order to solve this you will need to adjust the flash to fire at the end of the shutter opening. This is known as ‘Rear Curtain Sync’ or ‘2nd Curtain’.
‘Rear Curtain Sync’ is a little harder to master, but keep plugging away and the results will come.
Hopefully these tips will help you take some truly awesome pics. And if they do, why not enter them in our Nokia Low Light Photography Competition. Remember, you’ve got to be in it to win it!