The MTF-chart of the Zeiss Otus displays the contrast-curve at 10, 20 and 40 lp/mm (from top to bottom), which is a bit unusual. I’ll show you the real-life performance at 4 mm (center), 13 mm (APS-C/DX-corner), and 20 mm (FF/FX-corner) on a D810. The x-axis displays the distance from the optical axis (=center of the sensor) in mm. Higher values are better and the closer the dotted and the continuous lines of each color are together the less astigmatism (= resolution depends on the orientation of the test-pattern) the lens has.

These charts show the lens-performance at the largest aperture. Let’s have a look at the theoretical performance of the Zeiss Otus first compared to the performance of the Sigma 24mm f1.4 Art:Ībove left: Zeiss Otus 28/1.4 MTF at f1.4, right: Sigma 24/1.4 Art MTF at f1.4 100% crop, left = foreground, right = background The test revealed no relevant focus shift.Ībove: Zeiss Otus 28/1.4 Longitudinal Chromatic Aberration (loCA) at f1.4. The effect also shows up in real-life shots but is still pretty moderate. The coloration is a bit stronger than from the very good Sigma 24/1.4 Art which is a bit disappointing coming from a lens designated “apochromatic”. The new Zeiss Otus shows some magenta coloration in the foreground (left) and greenish hues in the background (right). With lenses offering an aperture of f2.8 or larger I test for longitudinal CA (loCA, a.k.a. Longitudinal Chromatic Aberration and focus shift

Zeiss siemens star test chart