The word 'bokeh' comes from the Japanese word 'boke', which means blur. It is pronounced “boh-ka”, or sometimes “boh-kay”.
Bokeh is technically used to describe the character or quality of the blur found in an image, but it is not the blur itself. It is the way the lens renders the parts of the image (that are outside its depth of field), into different shapes. The type of lens used determines the style of blades that open or close when the aperture is adjusted, which affects the shape and size of the visible bokeh. For example, a lens with circular shaped blades will lead to rounder bokeh, while a lens with hexagon-style blades will have appear more blocky and less orb-like.
Bokeh is usually captured in the highlights of an image (that often has strong shadows within the same image) and is commonly used to add softness to images. Sometimes when everything in an image is in focus, the eye tends to have a hard time trying to find what it needs to see. Bokeh can be used to direct the viewer’s eye directly to the subject by isolating it from the background. Some photographers use it to hide unappealing background elements from the final image.
"Good bokeh" refers to the blur quality that is often soft and creamy with no hard edges while “poor bokeh” refers to a blur that is unpleasant to the eye and often distracts from the main subject. Keep in mind that unlike aperture or shutter speed, the concept of what makes bokeh good or bad is entirely subjective. However, there are a few tips to keep in mind if you want to achieve what is generally considered to be “attractive” bokeh:
1) Bokeh is achieved by using a fast lens (lenses with very wide apertures with a minimum aperture of f/2.8) with a shallow depth of field. You should ideally use a prime lens which has a maximum aperture opening of f/1.8 or f/1.4, if you want to achieve good bokeh. If you don’t have a prime lens, try zooming in to the maximum focal length your lens allows to get a shallow depth of field, because longer focal lengths tend to enlarge the size of the bokeh.
When using a prime lens at a wide opening, make sure to check the focus of your final image. Sometimes when aiming to achieve bokeh in images, the actual subject may be slightly out of focus. Take a step back to make sure that your subject is still within the depth of field. If the subject isn’t focused in its entirety, close your aperture a bit until it appears sharp in comparison to the background.
2) When trying to incorporate bokeh into an image, you will need to set your camera to aperture priority or manual mode to give you more control over your lens opening. Set your aperture setting to the lowest value while making sure to adjust your shutter speed to get a well exposed photograph. When shooting at night, make sure that your ISO is below 1000 to avoid grainy photographs.
3) Make sure to get really close to your subject while increasing the distance between the subject and its background. The further away the background is, the more out of focus it will be. Try and aim for at least four metres or more between the subject and the background if possible.
4) Never use a plain wall as your background! Shoot your subject against a colourful background preferably with some lights in it. If you want to light your background, select lights that produce bright highlights with dark shadows. Christmas tree lights and fairy lights always help to produce good bokeh. Trees with light shining through the leaves, candles, the lights in a city skyline at night, or light bouncing off water, can work well too.
5) Get creative with your bokeh! Some people like to create customised bokeh by cutting shapes such as hearts or stars into black paper, and placing the paper over a prime lens like a hood cap (held in place by tape). This will have the effect of turning every highlight in the photo into the shape you’re using, just like in the photo below.
You may need to use a tripod when doing this activity because the paper will prevent light from entering the lens which can make the entire image blurry (not just the background).
However sometimes images where there is no subject, and the bokeh is the sole focal point, can turn out really well, like in the photo below.