Get a designer bokeh effect

Jason Parnell-Brookes demonstrates how to save time and effort on cutting out card by simulating your own digital bokeh shapes instead

Forget cutting out card – make your own digital bokeh shapes

Bokeh is defined in the OxfordEnglishDictionary as ‘the visual quality of the out-of-focus areas of a photographic image, especially as rendered by a particular lens.’

The way the glass in the lens disperses light produces different blurred areas, so too does the focal length of a lens, but the main factor determining bokeh shape is the diaphragm that forms the aperture.

Small blades converge to open up (f/2.8) or stop down (f/16) the aperture, and generally the greater the number of blades, the ‘creamier’ the quality of the bokeh, as out-of-focus highlights take on the shape formed by the aperture opening. However, by placing a cut-out shape in front of your lens while shooting wide open, these highlights will instead take on the shape of the cut-out, leading to all manner of creative possibilities.

You can use screw-on ‘starbright’ filters, etched with fine lines, to create star-like glints on shiny surfaces. Or you can craft a bespoke shape out of black card to tape onto the lens. However, we can fake any shape of bokeh we want with a digital image as the backdrop. From stars to heart shapes, there’s nothing we can’t turn into bokeh – and if you add a black acrylic board you can get twice the bokeh in the reflection.

We can take this further and use real-life scenes behind toy animals, which then look as if they’ve been green-screened into location. So let’s get started on our digital bokeh project.