Exciting times await smartphone photography enthusiasts. As we announced to you a few hours ago, Xiaomi has announced that on July 4 it will present to us a high-end mobile phone, the 12S Ultra, equipped with a main camera. 1 inch sensor Manufactured by Sony, model IMX989 and optics designed by Leica.

This won’t be the first mobile to bet on a 1-inch sensor. Sony, Leica and Sharp are some of the brands that have installed terminals equipped with a sensor of this size in their stores, but Xiaomi’s next move invites you to admit that perhaps the time has come for 1-inch sensors. start getting popular on smartphones.

And if so, that would be great news. The most distinctive feature of these sensors is that they are integrated. large photodiodes, so its performance in situations where ambient light is scarce is theoretically superior to that provided by sensors with smaller photoreceptors. Without going any further, the 1-inch 20-megapixel Exmor RS CMOS sensor in Sony Xperia PRO-I features 2.4µm photodiodes.

However, it’s not all good news. And making the most of the full potential of the 1-inch sensor in a smartphone isn’t easy. Xperia PRO-I perfectly illustrates this challenge, thanks to ZEISS optics. it only manages to cover the middle area of ​​the sensor, so the effective, usable resolution is approximately 12.2 megapixels in 4:3 format. The remaining 7.8 megapixels are not used, so in terms of resolution, the sensor is not used enough.

The limited space available in a mobile phone is a difficult challenge to overcome.

Fine-tuning high-quality optics is no easy task for a mobile phone that is bright and manages to minimize chromatic aberration and geometric distortion. And not first of all, because very limited space available in

Sony engineers could have supplied the Xperia PRO-I’s main camera with optics that could collect light and reflect it over the entire surface of the 1-inch sensor (they did on the RX100 VII camera), but this case is for this smartphone. would be noticeably thicker, heavier and perhaps larger. And most users would probably reject such a bump.

We’ve encountered two major problems of integrating a 1-inch sensor in a mobile phone before. If it coexists with conventional optics, some of its resolution is wasted, and if it works in conjunction with an optical block similar to what we can find in a compact camera, the volume and weight of the smartphone will be increased perceptible and neither brands nor users seem willing to accept it.

Fortunately, we have good reason to expect 1-inch sensors. they will find their place on mobile phones and along the way these two problems will eventually evaporate. This means that it will be possible to take advantage of the full resolution of the sensor without increasing the volume and weight of the terminal beyond what is reasonable.

At the end of last year, I had the opportunity to have a long and interesting conversation with Sebastian Doentgen, an optician who is currently one of the directors of consumer electronics at ZEISS. And, among other things, we address the challenges mobile optics manufacturers have to face in order to fine-tune them. quality solutions in the very limited space inside one of these terminals:

“The need to miniaturize the optics of mobile phone cameras seriously affects the choice of materials used to manufacture the optics. But on the other hand, the use of plastic lenses makes this possible. highly innovative optical designs it also has a very low cost,” explained Doentgen.

Plastic optical elements can provide higher levels of geometric distortion and chromatic aberration than glass lenses. Fortunately, corruption correction is usually does not represent a problem in the context of smartphone optics. Although optical hardware does cause significant residual degradation, it can be very convincingly fixed by software.

However, controlling chromatic aberration represents a much greater challenge because of the limited options manufacturers have when choosing the type of plastic to use in lens manufacture. Even so, once this issue is resolved, the need to run the optics is still on the table. cover the entire surface of the sensor without excessive volume.

A traditional linear lens doesn’t seem like the best companion for a 1-inch sensor, but periscopic targets It might be the solution we’re looking for. Sebastian explains this to us:

“If we stick with the traditional linear optics of smartphones, its length is definitely a limiting factor. And that’s because you can just stack it. limited edition lenses. We may be able to fit up to 8 or even 10 elements in the future, but given how limited space is in mobile phones, I’m not sure it will be possible to fit more elements into optics.”

“However, thanks to the development of periscope lenses, the rules of the game have completely changed as the vertical field limitation has been removed. In the horizontal dimension the space is not as limited as in the vertical dimension, so more optic stack. It will be interesting to see how this potential is used in the future,” Doentgen said happily.

That’s how things are. I reaffirm the prediction I made in the first lines of this article: exciting times are coming For users who love to take pictures with our mobile phone. We’ll see what Xiaomi has to offer us under the promising 12S Ultra umbrella in a few days, and we’ll satisfy our curiosity by exploring the strategy Leica has used to fine-tune the optics that will work side-by-side with the 1. This is the inch sensor of the mobile phone. We’re already rubbing our hands.

Cover photo: Burak Weekend