Have you noticed the blur of grass behind a child’s face in a portrait or the hazy glimmer of twinkle lights in a city shot— these are the parts of your image that refer to “bokeh” and that, in combination with your subject, brings your photos to life… (Featured image is for representational purpose and has been sourced from https://www.flickr.com/photos/thevlue/5284257536)
Have you noticed the blur of grass behind a child’s face in a portrait or the hazy glimmer of twinkle lights in a city shot — these are the parts of your image that refer to “bokeh” and that, in combination with your subject, brings your photos to life.
One Plus, in its latest One Plus 5 phone, and Apple, in its iPhone, offer dual camera to their customers; Samsung, in its SCH-B710 phone, allows users to click pictures in Portrait Mode – a feature which was first offered in DSLR cameras. A dual camera system includes one primary camera and one secondary camera. While the primary camera focuses on the main subject, the secondary camera offers depth to the background, allowing the main subject to stand out sharper. This is called the Bokeh Effect.
Apple was one of the early proponents of this technology, popularizing the Bokeh Effect in phone cameras. It has an interesting patent for this effect – US 9386299 B2 titled “Reference Image Techniques for 3D Sensing”. Granted in 2016, the patent describes a system comprising an image sensor or an external camera and an imaging device camera. The external camera, which is typically of a significantly higher quality than the device camera, provides at least one different optical characteristic, such as different fields of view, different resolution, different signal to noise ratio, and even different dynamic range. The external camera is leveraged to generate the reference image, while the device camera offers depth.
On the other hand, Samsung submitted a patent application in South Korean patent office in March 2016. The patent application, “Digital photographing apparatus and its operation method” (10-2017-0000311) describes a mobile device having a dual-camera setup in which one of the cameras is wide angle camera and one is telephoto lens camera.
As described in the figure below, the second camera (30) acquires a telephoto image (13) including the main subject (11). The second camera also acquires a shallow depth image in which a part of the main subject (11) appears clear and other subjects that are distant from the main subject appear blurred, resulting in the Bokeh Effect.
HTC filed a patent application US 9363499 B2 in June 2014 stating “Method, electronic device and medium for adjusting depth values”, which relates to Progressive Bokeh Effect. Once the focal length of a target object is obtained, a bokeh image can be generated by calculating the depth difference between the target object and other objects in the background. Consequently, the object the user selects is made clear, while other objects far from the selected object are blurred to generate a bokeh effect, as shown in the figure below.
The Bokeh Effect can create some beautiful backgrounds, without detracting too much from the subject. And although the opinions of what “good” bokeh vary from person to person, the most important thing is to explore the bokeh world by snapping good pictures.