periscope lens: Explained: What is Periscope Lens and how does it work in smartphones – Times of India

Apple is rumoured to introduce a Periscope lens in future iPhones. According to popular Apple analyst Ming-Chi Kuo, periscope lens will come to iPhones in 2023.
Incidentally, Periscope Zoom lens isn’t all that new. Smartphone brands like Huawei and Samsung already have Periscope lens in some of their flagship models. But, what is a Periscope lens and how does it offer zoom without jutting outside the smartphone’s body.
Here’s everything you need to know about smartphone’s Periscope Lens:
What is Periscope Lens
To understand the Periscope lens, let’s start with its history or rather origin. Periscope lens is a term often associated with submarines. Yes, in submarines these lenses or Periscope cameras are used to see what is going on the surface from within the water.
A Periscope lens is a setup of a couple of lenses along with two 45-degree angled lenses at each end of a long tube that reflects the image from the first 45-degree lens through all the other lenses in between to the second 45-degree lens that is located on viewers’ end in the straight line.
How does the Periscope Lens implementation in smartphone works
The first implementation of the Periscope Lens in smartphones was done by Huawei which introduced the 5x optical zoom. However, many argue that Sharp 902 which launched around 2002 was arguably the first phone to feature a Periscope Lens-like setup with 2x optical zoom using a single lens. Later Samsung also introduced the Periscope Lens with Galaxy S20 Ultra, the company calls it Space Zoom.
But the important thing is how smartphone brands managed to reduce the size of a Periscope Lens setup for smartphone’s relatively smaller form factor.
Here it’s important to understand how a regular smartphone’s camera works. Smartphone camera sensors are placed directly behind the sensor and the light falls directly through the lens to the sensor which captures the image.
In case of Periscope zoom camera setup in smartphones, the companies use 90-degree high-quality prism along with an array of lenses and sensor placed in a vertical arrangement. In this case, the sensor is placed in the 90-degree angle from the prism that we see at the back of the phone.
The entire setup is enclosed inside a rectangular housing which is small enough to fit inside a smartphone without protruding outside like a typical zoom lens.
How it zooms images
Most brands use the combination of prism and a folded optical zoom sensor like Samsung uses a 4x folded telephoto lens which zooms the image that’s being refracted by the prism which then falls on the sensor.
This has also enabled smartphone brands to implement a higher level of hybrid zoom. For instance, Samsung offers a 10x hybrid zoom via Periscope zoom lens using the internal algorithm.