HDR images & Traffic trails
Vary your exposure to balance out scenes or create ribbons of light
When shooting at night there will be places where the lights in one part of a scene can overpower those in other areas, making it impossible to record a balanced exposure in a single frame. Other than changing the bulbs, the only way to capture detail in the brightest highlights while still retaining detail elsewhere is to shoot two or more frames in perfect registration, then combine the exposures later for an HDR (High Dynamic Range) image. In our classic shot of Piccadilly Circus here, the advertising boards were much brighter than the rest of the lights, so first we took one frame with the shutter speed at 1/5 sec. This was fine for most of the scene, but the adverts were completely blown out. So we underexposed by four stops for the second frame (1/80 sec). Once done, we used Photoshop’s Merge to HDR Pro command to blend the two exposures for our final, more balanced scene.
Another example of unbalanced lighting occurs in car lights. Frontal headlights are much brighter than rear taillights, so for our creative twist on the scene here, we looked for a one-way street in which all the traffic would be heading away from the camera, got set up on a small traffic island, and then used a long exposure to transform the lights of passing cars, lorries and buses into beautiful ribbons of light snaking across the frame.