Essentially it is when a very large aperture is used (which produces a very narrow depth-of-field meaning the subject is sharp but the rest of the image is very blurry). Any background highlights or lights then are reflected as a large hazy (generally spherical) image.
I like this effect and have seen some excellent examples of it. I have recreated it around the home this month. Jenn has a bokeh kit - this allows cut out objects to be placed in front of the lens which then recreates this as the bokeh effect. See some examples below!
(Below): I focussed on the range hood's green on button - the background lights are typical of the bokeh effect
(Below): The bokeh effect is evident on the background lights (these are houses around 200m away)
(Below): Bokeh again in play - this time the out of focus highlights on the shrub
(Below): The starry curtains in Jonathan's room
(Below): For the following shots, I focussed on the candle in the foreground. The background candles are out of focus and the bokeh effect has been enhanced by choosing different cut out discs that sit in front of the lens. Sometimes this works really well and the cut out image is evident in many places!
(Below): The two images below are my favourites (the hearts and aircraft). Note the effect extends to light points in the background as well
(Below): Has one of the dogs left a light print, or is it the bokeh effect again?
(Below): The last two images are of the solar powered fairy lights we have outside, wrapped around our frangipani tree
