What is a liquid lens? It is commonly said to keep lenses away from liquids, but now a new technology called liquid lenses could revolutionize the future of mobile photography. Almost all mobile cameras use a fixed focal length lens. Companies usually have no choice but to increase the number of cameras and use a larger sensor to improve flexibility.
What is a liquid lens?
But liquid lenses have many benefits. These types of lenses use deformable fluids instead of physical disks. These types of lenses are very small and have a high speed. But what is a liquid lens after all, and how can it change mobile photography forever?
How do conventional lenses work?
Usually the flow of light through the camera lens is controlled by a set of parts. These curved discs — usually made of glass or percepex — are used to bend light when passing through the desired path. With the right distance between the lens and sensor elements, an image should be recorded clearly.
In general, when the electric focus motor is activated or rotated manually, the physical distance between these parts changes. In lenses based on variable focal length, users can also change the angle of view. Owners of DSLR or mirrorless cameras know full well that not every lens is suitable for all situations. Some lenses can zoom largely, but these lenses have much larger dimensions because they have to have many parts. If a lens doesn’t cover the right focal length, you should inevitably use a different lens.
In the meantime, prime lenses have a constant focal length, and most mobile cameras do. In the meantime, liquid lens with variable focal length can overcome many limitations and challenges.
How does liquid lens work?
Imagine a drop of water on the leaves. Most liquid lenses do not use any mechanical parts and instead contain a transparent liquid capsule. By applying pressure on a part of this liquid, its shape can be manipulated. The deformation of the liquid leads to a change in the path of light passage, resulting in a change in focal length.
The concept of liquid lens is implemented in different ways and often changes the shape of the liquid using electricity. One of the methods, known as electrowetting, is that water is combined with a separate layer of non-conductive oil that is placed next to each other in the lens. By applying voltage on the boundary between the two, the bending – and therefore the fracture effect – can be changed in a fraction of a second. Corning has produced lenses based on this technology.
Xiaomi uses a different method for the liquid lens of the folding phone, and thanks to this technology, the lens uses a minimum focus distance of 3 cm for macro shots, and on the other hand, it can enable 3x optical zoom.
What are the advantages of liquid lens technology?
Liquid lenses bring many advantages compared to conventional lenses. Their most important advantage is the possibility of changing focal length without using moving mechanical parts. This means the liquid lens can remain small and light.
These small dimensions make these lenses ideal for use in smartphones. As a result, companies using these types of lenses will no longer need to use multiple cameras, and only one camera can perform the task using different focal lengths. And if professional DSLR and mirrorless cameras can use this technology for their lenses, the size and weight of these lenses will decrease significantly and the flexibility of photographers will increase.
Given that most liquid lenses do not use electric motors, they are usually much faster than mechanical lenses in the field of focus. The fluid inside these lenses reacts almost instantaneously to the electric current, leading to the high accuracy and speed of the focusing process. The possibility of changing the focal length in seconds can provide photographers with a world of possibilities.
It should be noted that when the liquid lens does not use any mechanical parts, the durability increases because there are no moving parts for burnout. Removing these elements means reducing energy consumption, which should be good news for smartphone battery life. Also, regardless of the method used to manipulate the fluid inside the lens, the liquid itself is generally less sensitive to hand shaking than conventional lenses, which improves the lens vibration.
Like almost all lenses in mobile cameras, the aperture of the mobile lens remains constant. But thanks to the change in focal length, users can take advantage of better depth of field, and also, given that the liquid has a lot to say in terms of light transmission, the camera’s performance improves in low-light environments.
Which companies use liquid lenses?
Liquid lenses have been seen in industrial environments for several years due to their durability, small size and rapid reaction. For example, we can point to the Edmund Optics M12 lens, which is recommended for use in manufacturing systems that require high-speed machine vision. For example, in assembly lines before products come out of factories, these should be examined with great care. Thanks to liquid lens-based fast focusing, the M12 can adjust its focus at great speed compared to products rejected from underneath itself.
Although these lenses have several advantages for smartphones, Xiaomi’s folding phone is the first smartphone to take advantage of this type of lens, and as we said, it has not yet reached the global markets and only Chinese users can buy it.
When will we see more liquid lenses?
While liquid lenses are ideal for use in smartphones, the use of this technology in professional cameras poses far greater challenges. Focus speed is just one aspect of the camera’s performance. Even if these lenses for cameras are able to quickly change focal length, professional photographers need high quality photos in low-light environments, which is directly related to the size of the sensor.
But according to Edmund Optics, the largest aperture among liquid lenses is 16 mm, which means at best the 1.1.8-inch sensor can be used for it. So unless this technology progresses significantly, at least in the near future it won’t go the way of professional cameras.
But the technology soon appears to be widely used in smartphones. Huawei, for example, apparently wants to use this technology by registering various patents. Some rumors suggest that the Huawei P50 Pro Plus is using a liquid lens, which appears to be on its way to the market in a few months.
Xiaomi, on the other hand, prefers to use this technology for the first time in its expensive folding handset. It is likely that other companies will take the same approach and use this technology for one of their expensive handsets. Once the potential of liquid lenses for companies and users is proven, we will likely see the launch of phones based on just one camera in the not too distant future.
Given the current limitations, at least for the next few years we should not expect this technology to be used for professional photographic cameras. But given that smartphones are possible to use, this technology, along with powerful sensors, can revolutionize mobile photography and ring the latest death bell of compact photographic cameras.