Zoom burst

QI’ve seen an effect where the image looks like it’s radiating out from the centre of the frame. Is this a Photoshop effect?

AYou can create this appearance in Photoshop, but what you’re describing is a zoom burst, which involves moving a lens through its focal lengths during the exposure. The result can be very eye-catching, creating some dramatic movement in what would otherwise be a static subject.

You can use this technique on virtually any subject, but like all forms of intentional camera movement (ICM), it’s not always going to work successfully. As you have to use a slower shutter speed, it’s often worth putting your camera on a tripod, but if you have a steady hand or something to lean on then you can also do it while handholding the camera.

To make it work you need a slow shutter speed from about 1/15 sec or longer. Essentially, you move the lens through the focal range of your lens throughout the exposure, so you may need an ND filter to get a shutter speed that is slow enough in bright conditions. It takes practice to get the zooming motion smooth enough. The faster the shutter speed you use, the harder it becomes to do in the brief time the sensor is exposed.

To make a zoom burst stand out, I believe you need a subject with a good contrast range. For example, the lights of a city at night work well, or in the example shot here, a building illuminated in strong lighting, with tree branches and shadow helping to add interest. The zoom burst technique has been around for a long time, but it’s worth trying it from time to time to add something fresh to the scene you are shooting.