DxOMark has given very few cameras a score of 100 or more, including the D850 and a medium format camera. While the high score means the camera performed well in every category DxO tests for, the company said the stand-out feature is the sports score, which measures how well the camera handles low-light photos at high ISO.
DxO says only four other cameras have scored higher in the sports category and all of them have larger pixels. The more pixels you fit on a sensor, the smaller those pixels actually are, so higher pixel counts tend to translate into noisier images when shooting at high ISOs — for example, the 12-megapixel Sony a7S II is one of the cameras that scored higher. That high sports score is surprising since while the a7R III has a large full-frame sensor, it also packs 42.2 megapixels and higher resolution cameras tend to have more noise.
While the third camera in the a7R series has the same size and resolution as its predecessor, the a7R III still outscored the earlier camera by two points. DxOMark says that’s because of the landscape score, which measure’s the sensor’s dynamic range, or the range of light it can capture in one shot. Despite the similar specs between the two cameras, Sony did redesign the sensor with a new front-end microprocessor, helping the camera achieve a 10 fps burst speed. Sony also said a new anti-reflective coating on that sensor would improve the dynamic range and, according to the DxO tests, that claim is true.
Compared to the other 100 score in the database, the a7R III has better performance at high ISO while the D850 has better color and dynamic range when shooting at low ISOs, DxO Mark says.
DxOMark scores aren’t percentages, which means the a7R III didn’t get a perfect score — but the tests suggest photographers considering Sony’s latest flagship mirrorless won’t be disappointed by the image quality.
