Huawei and Samsung flagship mobile phones suffer severe image distortion
[May 27 Update: MingJian tests of Huawei P30 Pro revealed similar distortion and other issues in ultra-wide lens]
         In the course of the comprehensive lab test of the Best Camera Phones conducted at a top global imaging lab in Europe, MingJian uncovered that the 16mm ultrawide angle lens on the Huawei Mate 20 Pro and the 12mm ultrawide angle lens on the Samsung Galaxy S10 produce images with severe image distortion, chromatic aberration, digital artifacts and high image noise.

The benefit of an ultrawide angle lens is its wide field of vision, able to capture a panoramic display with a single shot, without the usual pan-and-scan image stitching. However, this often comes with a tradeoff, namely image distortion.

Digital camera test program leader, Dr. Markus Bautsch from Stiftung Warentest in Germany, shared the following example: “If you are taking pictures of high buildings with an ultrawide angle lens, the sides of the buildings are no longer straight, but rather start to curve the further away from the center of the image. In order to address distortion issues, all new mirrorless camera systems carry out automatic lens error compensation by default.” However, the ultrawide lens on both the Huawei and the Samsung lack any distortion compensation feature, resulting in extremely distorted images.

The mobile phone and camera markets have become increasingly intertwined as the top flagship smartphones add multiple lens and promise professional photo performance superior to compact cameras and rivaling DSLRs and mirrorless system cameras, in a device that is always close at hand. We decided to put the photo performance of the top mobile phones to the test by submitting five of the top flagship smartphones into our dedicated digital camera lab test for direct comparison against the leading compact cameras, bridge cameras, mirrorless system cameras and digital SLRs (Huawei Mate 20 Pro, Apple iPhone Xs, Samsung Galaxy S10, Google Pixel 3 XL and Huawei P20 Pro).

In the course of a comprehensive camera lab test of the flagship smartphones, MingJian uncovered that the ultrawide angle lens on the Huawei Mate 20 Pro and Samsung Galaxy S10 have significant flaws.


         The distortion and other imaging issues of the ultrawide lens are clearly visible in the images taken of the above reference chart in a lab-controlled low light environment with an illuminance level of 110 lux.

The gray edges of an undistorted image are straight and line up with the edges of the image frame, as seen in the top image below taken with the standard wide-angle lens of the iPhone Xs. However, in the middle and bottom images taken by the ultrawide lens of the Galaxy S10 and Mate 20 Pro, respectively, the corners of the chart curve in, revealing full reference arrows in each corner, where only the tips should be visible.

         As Dr. Bautsch points out: “Close observation of the test charts reveals that, in addition to extreme distortion, the images taken with the ultrawide lens also suffer from color fringes (chromatic aberration), high image noise, and a lot of digital artifacts. These issues are clearly visible zooming in on the lower left and upper right sections of the reference chart.
       Below are close-ups of the lower left section of the reference chart. The top image was taken with the regular wide-angle lens of the iPhone Xs, the center image was taken with the ultrawide lens of the Galaxy S10, and the bottom image with the ultrawide lens of the Mate 20 Pro.

In the Galaxy S10 image in the middle, notice the purplish light shadow next to the white arrows in the lower corner as well as along the arc of the half circle, this is chromatic aberration. Look at the grass of both the images from the S10 as well as the Mate 20 Pro and notice the loss of detail and blurring as compared to the image from the iPhone Xs. Look at the unnatural appearance of the pavement above the grass in the Mate 20 Pro image compared to the more accurate representation in the image taken by the iPhone Xs, these are digital artifacts. Additionally, the high image noise is clearly apparent in the image from the Mate 20 Pro.

         How does this affect photos taken of people? Look at the below close-ups of the upper right section of the test chart with the photo of the three models. Again, the top image is with the iPhone Xs wide-angle lens, the middle image with the Galaxy S10 ultrawide angle lens, and the bottom image with the Mate 20 Pro ultrawide angle lens.

In the top iPhone Xs image, despite a bit of graininess, the faces have natural skin tones and there is no distortion (notice how the edges of the photo align with the edge of the frame).

Compare with the center image from the Galaxy S10. The faces of the models have been unnaturally smoothed and no longer sharp. Also notice how the photo appears to be almost falling off the page, with the upper and right side edges distorted and top right corner hardly visible.

These attributes hold true for the bottom image from the Mate 20 Pro as well, however the faces have become almost artistic renderings and lose their contours and detail. Again the top corner disappears entirely into an abstraction of image noise.

         Although the performance of the standard wide-angle and telephoto lens on the Huawei Mate 20 Pro and Samsung Galaxy S10 is quite good, due to the distortion and other image issues of their ultrawide angle lens we cannot recommend the camera performance of either camera phone. Perhaps in the near future Huawei and Samsung will introduce image correction features in a software update to address these issues. Click to view all camera ratings.