Smartphones "dual camera": what these two objectives?

Forgotten race megapixels. The last picture innovation in the high-end smartphone, it is the dual objective devices. Gadget or real progress?
Two, it is necessarily better. LG G5 , Huawei P9, and soon iPhone 7. The last nec-plus-ultra high-end smartphones is to double the picture lenses. Before, there had been a first attempt with HTC M8 in 2014. What is this technology? The presence of two sensors it ensures better photographic quality?

In the interest of several lenses

Nowadays, photography and video are part of the first uses of the smartphone. Witness the explosion of social networks focused on sharing photos and videos, as Instagram and Snapchat. In France in 2015 the photo sharing is mentioned in 3rd position of the reasons to use social networks according to the annual study Credoc to ARCEP. 72% of 18-24 year olds take a photo at least once a week with their smartphone, according to Deloitte.

But the problem of the photo on smartphones is that you can not really zoom, for the good reason that there is no place, in housings, for a true optical zoom. Smartphones are almost cameras with a fixed lens. The digital zoom is nothing but an expansion, a crop which degrades the quality of the definition of the original image.

Nobody imagines add an unsightly bulge in a smartphone to accommodate a zoom. Although the Samsung Galaxy S4 Zoom, for example, was a good idea and made good pictures, the Korean has not renewed the experience of lack of commercial success. As for the clipper to photo accessories, whatever their quality, almost no one buys them.

LG G5

This is where smartphones "dual camera". A second lens adds photographic capabilities to the device, in the small space available. But, the process differs depending on manufacturers.

How to use the different models

LG G5. The latest addition to the LG range is equipped with a primary sensor of 16 megapixels at f1.8 and a second wide angle lens with f2.4 8 MP. The second objective is to shoot wide level, with a slight effect "fish eye" (distortion curve the edges of the image). On this unit, the two lenses are there to be used alternatively, as if the lens is changed on an SLR camera. Or both at the same time, thanks to software processing, for example a video with multiple angles in the same image.

Huawei P9

Huawei P9. Here, the two lenses show 12 megapixels and work in tandem to enhance overall image quality, recording data from the two sensors in parallel. One captures color, the other only in black and white. Two sensors is more data, so more details and sharpness. Huawei adds them to each other instead of a larger lens, which would capture more light thanks to its larger surface. The advantage of this system is that it also offers a special black and white mode, which does not bring much according to this test, but is very successful as this one .. Finally, the second sensor at Huawei also simulates the adjustment of a diaphragm opening to handle blurred.

HTC One M8. In the model of HTC, one of the two sensors were used only to manage the depth of field, another to capture the image.

HTC One M8

What do the experts say

They agree that the idea of dual sensor provides more, and above all, has a big potential. The wide angle of the G5 and is especially appreciated. The idea of Huawei also won. "The concept of dual camera module - one color, one black and white - is, we must admit, a brilliant idea that will allow smartphones to go tickle the APN standard of time and exceed some compact with small sensors, "concludes The Digital during his test.

"In the short term, it appears increasingly likely that the systems dual camera sensor will bring mobile photography beyond its current limits. When the processor technology to a core has reached the limit of its speed, hearts have been improved and finally multiplied. The same strategy would seem to apply to smartphone cameras, "The Verge analysis.

What will Apple do?

But it's not just the number of lenses that plays in photographic quality smartphones. Thus, the Galaxy S7 always going to be the best - or one of the best - smartphone for photography, and he has only one sensor.

Which brings us to the big question: what Apple will do its two sensors? Maybe "the next big thing" of the photo on smartphone ... In April 2015, Apple bought LinX, an Israeli company that has developed a multi-sensor photo technology for smartphones, promising to miniaturize the sensors to improve the triggering speed, the pictures in low light, and even to obtain the correct post-taking views and 3D shooting. It promises.