Zoom blur is a popular bit tricky little technique where you zoom the lens during the exposure so that you get a kind of radial blur from the centre of the picture. This means using a shutter speed long enough to capture this rapid zoom movement, which usually means you get plenty of regular blur too. You can even add another twist, rather literally. As well as zooming the lens, you twist the camera round so that the blur turns into a spiral.
But if all this is just too tricky, you can just cheat and do it digitally. Lots of different image-editing programs have blur and spin tools that can do the job, but the one I’m using here is Analog Efex Pro.
So here’s my start shot (below), taken in a boxing gym during a training session.
I’ve caught the boxer between punches, so that although the picture is sharp it also looks a bit static. That’s what I need to fix in Analog Efex Pro, and here’s an annotation showing how the Zoom & Rotate Blur filter works. (Note that you have to be in the Camera Kit mode to select filters individually.)
01: Analog Efex Pro’s Zoom & Rotate Blur filter displays an on-screen gadget where you can make all your adjustments ‘live’. You drag it around using this centre ‘pin’, and I’ve positioned it over the boxer’s face, which needs to be the focal point of the picture. Within the gadget’s inner circle, everything will stay sharp. You can change the size of this circle by dragging inwards and outwards on its rim.
02: The outer circle marks the boundary for the zoom and rotate effect. Outside this, the picture is fully blurred. The zone between the inner and outer rings is where the zoom blur effect is progressively blended in. You’ll see there are spiral arms in this area too, and they represent the ‘spin’ that’s been applied. You apply the spin using any one of the four blue control nodes on the outer ring.
03: All the changes you make with this gadget are reflected in the sliders in this tool panel on the right. Indeed, if you don’t like using the on-screen gadget, you can use these instead.
So here’s the finished picture. The blur has been added artificially, but it still gives a strong sense of movement that the original, static picture lacks. I like the way the twist blur has given the boxer’s right hand a strong upward movement. The blur has been exaggerated a little for effect here, but it’s easy enough to adjust the strength to suit your subject and your taste.