I already reviewed Sigma 35mm 1:1.4 DG Art HSM and Carl Zeiss Distagon 35/2 ZE.
But the question what lense has bigger resolution on frame center, remains open. As well as the data on resolution measured numerically. We will also try to close this gap today.
Except specks of 100% from frame center, there will be a numerical measurement in couples of lines on 1mm. The distance to a target recommended for the test program Imatest, 50. I.e., in this case, 175sm.
Measurement of lenses resolution was taken for contrast of MTF50. They can’t be compared to permissions of the Soviet lenses for which it was accepted to take measurements for MTF20, i.e. in the facilitated conditions.
The camera on a tripod, is aligned on level. The target is lit with the studio Broncolor Grafit A4 generator with high color temperature accuracy of light in case of power change (unavailable to sources of constant light). Also it will be in one position, i.e. the target “is frozen” by a short burst flag pulse. The camera works on the radio synchronizer to exclude relocation of the camera (Canon 5D mark II) during the test.
All crops turned out not the really informative during the tests of 35mm lenses from distance 1.75m. Therefore I suggest to study the diagram of numerical values.
According to the diagram it is visible that Sigma 35mm 1:1.4 DG Art HSM advances Zeiss Distagon 35/2 ZE on resolution. But, pay attention that on F4 and F5.6 they are completely identical. If to give a discount for focus-shift at Zeiss Distagon 35/2 ZE, most likely, they are very close.
Here we measured optics resolution, i.e. ability to distinguish fine details. For determination of lens contrast range(for example, MTF10, MTF20) we need additional measurements. In my opinion, Zeiss was more contrasting, but so far it — is subjective.
One of the most important points is focus-shift on the lens Carl Zeiss Distagon 35/2 ZE. I.e. in case of change of value of a diaphragm the focus significantly displaces. Therefore every time was necessary to be refocused. For real shooting it not a problem since all of you equally are always refocused in case of each new plot.
The second moment — at the tested lens Sigma 35mm 1:1.4 DG Art HSM isn’t present any problems with an autofocus about which some readers / users spoke. Focusing is very exact.
The third moment — cross HA (violet borders with the edge of a frame on contrasting objects) are visible on the lens Zeiss Distagon 35/2 ZE.
Fourth moment. I compared only lenses resolution and only on frame center. Many other interesting parameters, such as resolution at the edges of a frame, distortion, vignetting, contrast stayed behind scenes. If parameters are important for you, in this test they aren’t affected. I can only tell that lenses strongly differ in the called parameters.
Plus, I compared Sigma 35/1.4 with Zeiss (35/2) which was available. It would be more correct to compare to Zeiss 35/1.4, but I didn’t have it at thet moment.