The optical zoom of smartphones works through a set of lenses that, when they are far apart, can enlarge the image without losing quality. It is thanks to the periscope system that smartphones today have this feature and remain thin and light.
Learn a little more about optical zoom, the difference to digital and the advantages of using the periscope camera module to ensure more range.
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What is the difference between digital zoom and optical zoom?
Before understanding how optical zoom works in more detail, it is important to understand that there are two ways to use the zoom feature on a smartphone, digital and optical. In this case, optical zoom is a more modern and advanced option, which guarantees more quality.
That’s because in digital zoom the process happens in a more simplified way, not having much to do with the camera’s hardware, but with the software. That is, it is a program on the smartphone that simply zooms in on the image. With this, it greatly reduces the quality of this image and also the sharpness. The higher the zoom, the worse the image gets.
It’s like taking a photo on a computer or smartphone screen and manually zooming in, zooming in on some point. The more it is enlarged, the worse the quality becomes as the number of pixels decreases.
Nowadays many smartphone sensors have great power and a number of megapixels that, even when zooming 2x or 3x, still manage to maintain a good quality because even reducing the number of pixels, it still maintains a decent range. But you can’t zoom bigger without having big losses.
That’s where optical zoom comes in. It does not use software but the camera hardware itself. In practice, he manages to increase the distance between the sets of camera lenses of the device so that they can guarantee a real approximation of the image when taking the photo.
In this case, it maintains the quality of the photograph or video recording even during zoom, since the zoom is made through the lens and not through the sensor. The disadvantage in this case is that these cameras have a smaller aperture, that is, little light enters and therefore the images may come out a little darker.
Periscope system ensures zoom on thin smartphones
For smartphones to be able to give a quality optical zoom, the lenses need to be further away from the corresponding sensor. Currently the telephoto camera module is responsible for this function, and comes with about 5 to 6 lenses that can be plastic or glass.
This makes the images can be zoomed in without the camera losing its original quality, since the lens is the one doing this and not a zoom program afterwards. So, if the user zooms in more than 2x, the device itself automatically uses the telephoto main lens for that.
But smartphones that rely only on telephoto do not have much approximation capacity because of the physical space. To get closer, the lenses need to be further apart and that means a thick module, which wouldn’t sell well these days.
This is where the periscope system comes in, a practice widely used by companies today. It works in exactly the same way as the original periscope, usually those used on submarines. It is used so that someone inside a submarine can see what is happening on the surface of the sea, and for that reason it has a set of several mirrors positioned at 45 degree angles in parallel so that the image can be reflected from one to the other. another until you reach whoever is looking down there.
On the smartphone it happens more or less that. The main objective is to form a set of lenses that are separate, but do not need to be stacked. They are distributed horizontally and perpendicular to the sensor rather than directly over it. For this, prisms and mirrors are used that manage to redirect light through the device, making it pass through the lens and reach the sensor. In this case, enlarged.
That is, instead of taking up a lot of space on the device with a stacked format of lenses, the periscope system allows this system to “spread” across the width of the device and also makes them even further away, increasing the zoom capacity. from the camera. All this without distortions and maintaining the image quality.
As the lens assembly is positioned horizontally, manufacturers use these prisms at the ends. In this way, the light can be refracted by the lenses until it reaches the sensor, which, in this case, is positioned standing up instead of lying down, as in common sets.
With the use of this system, some manufacturers are still able to make some changes and improvements to their devices. This is the case of Samsung, for example, which uses a small change in the periscope system to further reduce the physical space it uses inside the smartphone.
In this case she uses two prisms. The first works to allow light to pass through the lens like the others, and the second is positioned very close to the sensor to deflect light downwards, which helps to save space.
Can you tell if a camera has the periscope system?
The answer is yes. Just by looking at the camera set of a smartphone, it is possible to know if it has the periscope system or not.
This system is recognized because of its rectangular shape in the telephoto camera. Some companies even put a more rounded edge, but you can see that it’s not completely round. This happens because of the positioning of the prism, which differentiates the periscope camera from the others.
In this case, the attempts to make the edges more rounded and the modules darker is a way that companies found to try to standardize the set of cameras without differentiating the lenses too much. In other words, something entirely aesthetic.
Optical zoom guarantees great quality and range, but is an expensive component
Smartphones that have an optical zoom and periscope system for greater range are usually the most premium or top-of-the-line smartphones. That’s because this system is not cheap, so it ends up costing more to be implanted in a device.
This may improve over time, as companies add more advanced features, optical zoom could reach other devices, such as intermediate ones, in the coming years, thus becoming a more popular feature.
Currently one of the manufacturers that stand out in this market is Samsung, as it offers smartphones with great zoom powers. Using the periscope system camera module, they even add high resolution sensors. This causes the zoom to reach numbers like 100x magnification. This is because since the sensors have a large number of pixels, it is still possible to add the digital zoom feature without losing much quality, guaranteeing interesting results.