The Long Exposure mode on your phone camera works in a similar way, but it's no longer the complicated process it used to be. Now, you can take professional-looking action shots with just one tap ...

4. Expose for contrast To make light trails stand out, we need high levels of contrast. Choose an open aperture (small f-stop) but avoid extremely long exposures.

A long exposure photograph is taken with the artist moving the LED array in front of the camera - the flash becoming a dot on the photograph.