The second lens on the camera normally help create the bokeh effect or enhance the depth perception of an image. It focuses on the primary object or person in the photo and blurs the background.
Different companies make it available in their camera software in different ways. Some simple label it ‘portrait’, other call in ‘bokeh’ or it can be activated using a toggle labeled ‘enhance depth’ or ‘in-depth’.
The efficiency or ‘natural-ness’ of the bokeh effect also varies from phone to phone. ‘Good bokeh’ is when the transition between the in-focus and out-of-focus objects is smooth. ‘Bad bokeh’ is when the blurring effect distracts from the item in focus.
Widening the frame
The most popular choice for the third camera is a wide-angle lens. It widens the frame capturing more details in a single frame.
Wide angle lenses generally have a focal length that is shorter than the focal length on a normal lens.
It is popularly used to capture cityscapes, landscapes and architecture.
On Samsung phones, it can be found a toggle near the base of the screen where you can choose between a smaller frame — displayed as two trees — or a wider frame — displayed as three trees.
On some other phones, it’s a swipe to the left or right. The remainder normally have a toggle on top of the screen to widen the frame.
Though most companies use a depth sensor for the bokeh effect, it can also be brought out using wide angle lenses.
Zooming in — the right way
There are two ways that smartphone zoom in to capture an image — using optical or digital zoom. Digital zoom is rarely effective and blurs the image even when the camera is stable.
Optical zoom, on the other hand, allows the user to capture a closer image without losing the details.
This is made possible using a telephoto lens. The addition of telephoto lenses also improves the quality of bokeh shots since the camera software has more accurate data to work from.
The monochrome sensor
Some phones employ a monochrome sensor instead of the other two options. The sensor makes images more sharp since it captures black and white more effectively.
So when it’s used to capture a coloured image, the colour accuracy in the image is better and the edges of objects are better defined.
A monochrome sensor is still a relatively rare find on smartphones, though it’s most popular choice for the fourth sensor on quad camera phone.