Vivo turned to German optics manufacturer Zeiss for its X80 Pro. We explained in concrete terms what this partnership was able to bring and what their approach was.
During a meeting with engineers from Zeiss, we were able to better understand what the Chinese smartphone brand gained from this partnership. Because neither the lenses nor the optics were made by the German imaging specialist. No, his role is elsewhere. This is to provide expertise in three areas (among others): color quality, definition, and anti-reflective coatings. We offer here a brief description of the three.
Please note that everything we are shown here is not a trade secret and therefore there is reason to think that it is just the tip of the iceberg. However, these elements help to better understand the approach of optical specialists working on smartphones.
A can of Coca-Cola and a Milka tablet to test the colors
The first tool used by the Zeiss engineers that we wanted to show you is a simple box that allows certain colors to be faithfully reproduced and whose lighting can be varied. Here, for example, Zeiss showed us a box that allowed us to test 18 colors. The interest is to see how much the colors vary when the lighting gets hotter, for example. Green, for example, tends to vary little. It is on this basis that engineers will be able to work.
“What we’re trying to replicate isn’t a physical measure of color, it’s a combination of lighting and how color is received by the eye.”explains David Abreu, a Zeiss engineer, during a meeting with the press. frandroid participated in it.
Then comes a second proof, still in color, such an important subject. It begins in a curious way with a painting that notably contains a can of Coca-Cola, a piece of grass or even a Milka chocolate bar. If this sounds a bit ridiculous, it’s actually very serious.
” There are so-called memory colors.says the Zeiss engineer. These are colors that we know users are going to have expectations of. They are also the ones that will jump at you right away. »
We are thinking here, for example, of the green of the grass, the purple of the chocolate bar or the characteristic red of the can. Beyond the anecdote, these are colors anchored in everyone’s memory. In addition, the engineer becomes a philosopher for a time when he explains to us: “People remember these colors well, but not necessarily in the same way as what you actually see in the scene. There may also be variations between world regions. It is something we measure. » That is why Vivo has decided to leave the choice between natural colors (called Zeiss colors) or those that are a little more striking, but sought after by the largest number.
Other objects in this box respond to a different problem. We have, for example, a sheet of aluminum foil that allows ” test very localized light sources with high intensity“, details David Abreu more. We can also distinguish a brush, which allows us to measure the reproduction of details well.
How to prove the definition
Zeiss engineers also showed us how they test the definition of an image. The objective is simple: to avoid deformations as much as possible. The test is based this time on a set of circles with black and white stripes. The goal is that the closer we get to the center of the circle, the more difficult the definition will be to distinguish.
The other interest of this test is that it allows to distinguish if there is asymmetry or problems in the edges of the image. In fact, it is not difficult to notice an anomaly in perfect lines.
Anti-reflective coating to play with light
If you have taken a good look at the back of the latest Vivo X80 Pro, you may have noticed a strange red “T*” symbol.
The presence of this T* is intended to inform the consumer that the lenses of this device are covered with a special coating. Coating consists of applying a very thin layer (less than one µm) of a very specific texture to a lens.
Its purpose is essentially to reduce reflections created by lenses. It sounds simple like that, but it’s a big deal. “In any lens, 95% of the light passes through. You could say ‘not so bad’, but the problem is when you start placing several in a row. » We can for example have a lens in the middle of all the others that reflects 5% of its light towards the previous one, which returns towards the later one, and so on.
So we also get alens flarethis famous effect so loved by JJ Abrams, director ofStar Warsepisode 7. When this is mastered, there may be some aesthetics, but in general it is a flaw in an image that Zeiss promises to correct by applying a coating to the lenses.
Glare reduction has other virtues. One thinks, for example, of a considerable increase in contrasts, because the amount of diffuse light in the image is better controlled.
What is the difference with Leica and Hasselblad?
This work on the lens, even if it is content to add a small layer, seems to us for once a specificity of the partnership between Zeiss and Vivo. As far as we know, Hasselblad is content to help Oppo and OnePlus with color calibration, while the exact extent of the partnership between Leica and Xiaomi is not yet known.
On the other hand, it is likely that the color procedures or definition that we have just presented to you are generally the same as those of other manufacturers. It should be added that many manufacturers such as Samsung, Apple or Honor do not use this type of collaboration, which does not prevent them from being well placed in the different rankings of best camera phones.
NB. This article was written as part of a press trip organized by Vivo to Berlin, with equipment from Zeiss.
To follow us, we invite you to download our app for Android and iOS. You can read our articles, archives and watch our latest YouTube videos.