Dual camera setup on smartphones explained: Telephoto, Wide angle and more

Telephoto lens

This is one of my favorite implementation of the dual camera setup. If we look at the prime example as the Apple iPhone X, the smartphone has a dual 12 MP cameras, where the primary camera has an aperture of /1.8 and the secondary depth sensor has an aperture of f/2.4. The telephoto lens comes with different focal length, in this case, the primary sensor has a 28mm focal length, whereas the secondary camera has a 32mm focal length. Due to the difference in focal length, the secondary camera can offer 2x optical zoom. In case of portrait mode, the primary camera and the secondary camera will capture a different image and the software algorithm will stitch both images and will blur the background to offer an image with depth of field.

Wide angle lens

This is again my favorite dual camera implementation. This setup is seen on the Asus ZenFone 5z. In this scenario, the primary camera is being used to capture normal photos and even the portrait mode is achieved using a single camera using a software algorithm. The secondary wide angle lens (as the name suggests) comes with a 120-degree field of view, whereas the main camera comes with 89-degree field of view. The secondary wide angle lens can capture more scenery on a single frame.

Monochrome sensor

This setup is generally found on the Honor/Huawei smartphones. The Honor 10 does have a dual camera setup with a standard camera and a monochrome sensor. The device has a 16 MP primary RGB sensor and a 24 MP secondary monochrome sensor, which captures images with rich details with no color information. One can use these monochrome images as it is or the device can create a bokeh effect using the data from the secondary monochrome sensor.

Depth sensor

Most of the affordable mid-tier smartphones will come either with a 2 MP or a 5 MP depth sensor. On the Xiaomi Redmi Note 5 Pro, the smartphone has a 12 MP RGB sensor and a 5 MP depth sensor, which is being used to capture details to create bokeh effect or depth effect. The details captured on the secondary camera will help for edge detection to offer seamless photos with blurred background. The Honor Play has a 2 MP depth sensor, the Xiaomi Redmi Note 5 Pro has a 5 MP depth sensor, whereas the Xiaomi Mi A2 and the OnePlus 6 has a 20 MP depth sensor. All these depth sensors have a single job, that is to improve portrait mode.

Low light sensor

The OnePlus 5T is the right example for explaining the dual camera setup with a low light sensor and is probably the only smartphone to do so. On the OnePlus 5T, there is a 16 MP primary camera and a 20 MP secondary camera, which only works in low light (less than 10 lux of light). However, it did not have much of an application and the company is using a depth sensor on the OnePlus 6.

Conclusion

There are other smartphones with dual camera setup consisting of a heat-sensor (Cat S60) and 3D sensor (HTC Evo 3D). However, these technologies have not been used on general smartphones. So, which dual camera setup technology does your smartphone has?