The new kid in town is from an established player in camera measurements: DxO Labs. The company, which performs detailed tests of cameras and sells software for editing raw photos, is revamping its DxOMark site to offer lens tests as well as the earlier image sensor tests.
It's got some significant differences over established reviews sites. First, it adds a parameter the others lack, transmission, which measures how much light actually makes it through the lens. For example, Canon's EF 50mm f/1.8 II lens actually has an effective maximum aperture more like f2.1, DxO's tests show.
Second--and this is the bigger difference--the tests show how each lens works on a wide range of camera bodies; existing lens sites typically run tests just on one or two bodies. Seeing how a lens works differently on different bodies can help inform prospective buyers whether a high-end lens is worth its premium on a lower-end camera, or how well an existing lens collection will work on a new camera body. … Read more