When a customer chooses which smartphone to buy, the quality of the built-in camera is often an important factor for consideration. Many smartphone cameras are now so powerful that in many cases they rival, and even outperform, the average compact cameras.

The DxOMark, a website known for its camera reviews, has released its latest ranking of the smartphone cameras currently on the market. Sony Xperia Z2's high-quality camera surpassed the evergreen 41-megapixel camera on the Nokia 808 and climbed to the top of the best smartphone camera rankings.

Sony's new gadget achieved the highest DxOMark Mobile score to date of 79 points. It took the top spot by two points compared with Nokia 808's 77 points.

As a revised version of the Xperia Z and Z1, the Xperia Z2 boasts a 1/2.3-inch type BSI CMOS sensor, with a 20.7-megapixel resolution and high-grade G-type lens in a waterproof shell. Its color and detail preservation are very impressive, both outdoors and when set in more challenging lighting. It also offers significantly upgraded movie capabilities with 4K (3840 x 2160) video over its predecessor. "Noise levels remain low," and "only some fine-grained luminance type noise is noticeable at times," the report said.

The following are the top 10 smartphone cameras currently on the market.

 Samsung Galaxy Note II

Samsung Galaxy Note II [File photo]

Overall score: 72

Photo: 73

-- Exposure and contrast: 81

-- Color: 77

-- Autofocus: 74

-- Texture: 64

-- Noise: 69

-- Artifacts: 78

-- Flash: 70

Video: 71

-- Exposure and contrast: 87

-- Color: 83

-- Autofocus: 58

-- Texture: 66

-- Noise: 61

-- Artifacts: 90

-- Stabilization: 45