Real world meets lab
The lenses on test differ in many respects, but we tested them in a consistent way
To test real-world performance, we use lenses in wide-ranging lighting conditions on a variety of different camera bodies. We check for good build quality and handling, smooth and precise operation of zoom and focus rings, and test the effectiveness and accuracy of autofocus and optical stabilisers.
We also run a full range of lab tests under controlled conditions, using the Imatest Master and DxO Analyser suites. Photos of test charts are taken across the range of apertures and focal lengths and analysed for sharpness, distortion and chromatic aberrations (colour fringing). A summary of these results is shown towards the end of the group test, but we also take data from a wider range of apertures and zoom settings into consideration. Finally, we combine the lab tests and real-world shooting results to give overall ratings.