Monday, November 28, 2016

Lab – Google-Pixel : photos very dependent on the HDR – The Digital

the Second round for the Google Pixel and Pixel XL in our lab ; after their good displays, it is the turn of their cameras to sift through our tests. Far from being bad, the smartphones of Google, however, show some weaknesses compared to the competition.

as a reminder, the Google Pixel and Pixel XL ship with the same modules photo. At the rear, there is a sensor of 12 Mp surmounted by an optical non-stabilized with an aperture of f/2. In terms of definition, the competition also offers the 12 Mp on the iPhone 7 or the Galaxy S7, while the LG G5 and OnePlus 3T make the choice of a sensor of 16 Mp. It is mostly on the side of the optic that the Pixel does not shine in the face of these competitors : the iPhone 7 has a optical stabilized aperture f/1.8, just like the G5 ; the GS7 keeps him as the stabilization and opens to f/1.7 ; the OP3T, for its part, also focuses on the optical stabilization, but offers an opening equivalent to that of the Pixel.

However, these data are only part of the equation photo, the other variable almost as important as software. The Google Pixel are perfect examples of that image processing can come to fill some technical gaps, but it is to be paid at one time or another.

Quality of image : an HDR mode+ powerful, but not flawless

The HDR (High Dynamic Range) has become a feature ubiquitous on smartphones. This treatment can offer, as its name indicates, a better dynamic to the shots, that is to say a difference between the highlights and shadows. In practice, this allows to get a photo exposed evenly without dark areas that are blocked or that the brightest parts are to be burned. Like any software processing, the HDR is often accompanied by disadvantages such as the loss of image quality or capture a more slow, for example.

The use of such a process must therefore be adapted to the situation and it is preferable to activate that when necessary. The Pixel land by default with their HDR mode+ automatic, that is to say, it will only be used if need arises. Well, in theory. In practice, even set to auto, the HDR is triggered every time, even in conditions for which it is not essential.

We found very quickly the reason for this by comparing shots with and without HDR+ Pixel. The overall HDR photos is more pleasant and the treatment fulfills its proper function by managing the exposure of the different areas of the image so that it’s supposed to. However, there is a certain tendency to under-exposure of the white areas appearing clear greyish. The interest of the HDR is to be found here especially in the level of detail, thanks to a better management of the electronic noise. The HDR mode also tends to give colour less neutral, more supported. Chromatic aberrations are quite present on some grounds.

On the plan of the quality of pure image, the Pixel and Pixel XL arrive overall at a level comparable to that of a Galaxy S7 edge, or a LG G5. These, however, retain an advantage when it comes to responsiveness. As mentioned above, the use of the HDR+ has the bad habit to lengthen the time of capture and processing. It becomes more complicated to perform the photography without the Pixel start to a great ride. Once the photo is captured, it is not uncommon to have to wait between 1 to 5 seconds before being able to view this, depending on the number of shots taken. A problem eliminated when we completely disables the HDR+.

The development displays also a slight delay on one of the competitors. The accuracy and the speed of the autofocus of a Galaxy S7 will remain out of reach for the Pixels, while the LG G5 keeps him as a short head in front in terms of responsiveness.

In low light, the HDR becomes essential

If the use of HDR in full light depends on the expectations of the photographer and the situation, it becomes essential when the light is scarce. Without this function, the electronic noise whitecaps merrily on the totality of the picture, leaving a little room for chromatic aberrations in solid black. In these conditions, we could compare the performance of the Pixel to those of entry level smartphones, offering snapshots simply unusable.

Note that, although essential in low light, the HDR does not get rid of its through as described above. The responsiveness is worth it and the treatment even longer. On this point, G5 and S7 edge manage to maintain their velocity, and this, without common measurement with the Pixel.

The HDR mode+ does not eliminate the electronic noise, but the tempers somewhat. The contours are less drafts and the details more numerous, but the black planes are very heterogeneous. It would seem that the Pixel is refuse to any smoothing, as opposed to the competitors. Again, the GS7 edge and G5 are placed far ahead of the smartphone from Google, with a treatment course more to this, but made it more flattering.

The video is disappointing in any light

The Google Pixel are capable of filming in HD (720p), Full HD (1080p at 60 or 30 i/s) and UHD (2 160p). If the first mode is very well managed, the other 2 seem to cause more problems. First problem, in Full HD, 60 fps, electronic stabilization gives an almost surreal images ; especially, in spite of a SoC Snapdragon 821, the Pixel has some problems to stay perfectly smooth. It is better to prefer the mode 30 i/s, is less prone to glitches and more natural in the rendering.

The transition to the video TECHNOLOGY poses other pitfalls on the path of the Pixel. Stuttering and other slowdowns are still in the game, but the most annoying here, it is the electronic noise that appears rapidly.

The focus tracking is not the most powerful either, only the exposure measurements are correct during video recording.

A very good module front-end

The module before the Google Pixel and Pixel XL displays 8 Megapixels on its sensor. This is the definition that we now find regularly on the smartphones of this range. This sensor front-end delivers a very good service, with a level of detail that is of the highest caliber and an image-processing reduces just as it should be. Here, no smoothing, over-reaching, big eyes, or whitening of the skin. The self-portraits are captured and displayed a natural and a very good dynamic range, the backlight does not make him afraid.

If we compare to the module before a Galaxy S7 edge, the Pixel is doing extremely well. Of course the angle of view is less wide with the Pixel, but this allows for a deformation of subjects which are less important than on the GS7 edge. In addition, the 8 Mp provide much more detail on the Pixel.

A photo app is very limited

manufacturers are increasingly numerous to offer a multitude of settings in their photo applications. Manual Mode, filters, panoramas, or effects of depth-of-field so it has become almost inescapable on our smartphones. Only Apple makes of the resistance by locking as much as possible the settings offered to the user. Google follows unfortunately the same direction, and the Pixel are restricted.
the Point of manual mode to be put in the tooth, only a vague setting of the white balance is accessible, as well as a slider for exposure. So you can not adjust the aperture or the shutter speed, as proposed by Samsung, LG or Huawei. Too bad for those who want to go a little further than mere cliché is subjected to the software processing of the device.

On the other hand, Google gave in to the temptation of the simulation of depth-of-field, with a mode called “fact focus”. If Apple and Huawei also propose a similar process on the P9, Matte 9 and iPhone 7 Plus, these devices exploit the dual module to reach their goal and evaluate the distances between the planes. Here, the single module photo needs to find another parade, in the form of a displacement of the device towards the top.

This process is both impractical and inefficient. As the competitors mentioned above, in the Pixel have a lot of trouble to detach with realism a subject positioned in the foreground from its background. When the colors of the subject and what lies behind it are too close, the treatment does not know how to locate the area to be blurred with precision and it is not uncommon to have elements not treated as they should be.

Conclusion : a slight disappointment on arrival

While many north american media have praised the performance in the photo of the Google Pixel and Pixel XL — the latter even showing the best score ever achieved by a smartphone in the tests DxO —, we stay our hand a little on our hunger. Of course, the Pixel displayed some advantages, such as an HDR mode+ performant enough, but when one focuses a bit more on the negatives, the faults are present as well. A bit like iPhone 7, the Pixels are smart phones that will delight users who want a maximum of simplicity and whose shots will not go out of the frame of the viewing on a smartphone or are online on Facebook or Instagram.

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