Close Range Tests (f1.4)

Close Range Test Procedure

The following  tests results were assessed on a flat-field target, and were only possible with extensive and time consuming micro adjusted focus bracketing in which more than 100 RAW files were processed via Capture One. Apertures tested were f1.4, f2.8 and f8 using a Canon 5D. Lighting was via a single flash unit fired through a Cubelite. Focus confirmation was double-checked with a tape measure running diagonally through the plane of focus.

Full frame. Test sample areas highlighted in red.

Resolution/Performance at f1.4

Zeiss ZF 85mm f1.4 ar f1.4 (centre)
41,123 bytes
Canon 85mm L (Mark 1) f1.42 ar f1.4 (centre)
49,148 bytes

Though it pains me to say it, the Zeiss ZF 85mm is really very poorly corrected for close range work compared to the Canon L. I can’t rule out an adaptor problem, but if the adaptor is to blame, then it’s not going to excel on Canon bodies. The corners reveal similar problems.

Zeiss ZF 85mm f1.4 ar f1.4 (corner)
17,150 bytes
Canon 85mm L (Mark 1) f1.42 ar f1.4 (corner)
20,530 bytes

No matter how long I tried, I couldn’t get a better close range shot than this with the Zeiss. I aborted two tests before this realising the truth. Mid-range testing – and the crucial distance seems to be about 2m – tells a different story. To confirm the focus, and illustrate the problem, here is the tape:

Zeiss ZF 85mm f1.4 ar f1.4 ( Canon 85mm L (Mark 1) f1.42 ar f1.4

At f1.4, the Canon lets you know exactly where the focus is. By comparison the Zeiss is so unsharp, it’s anybody’s guess where it is: 43.7mm? 44.5mm? Interestingly, the Zeiss 85mm manages to pull of the trick of rendering defocused areas more legibly than the depth of field should permit – giving it greater apparent DOF for the aperture – a trick that makes their wide angles so great for interiors, but how much better portraits would be with the Canon’s sharply defined focal plane and stronger bokeh mojo.