Lab Tests
Please note that MTF50 results for APS-C and Full-Frame cameras are not cross-comparable despite the same normalized [0:1] range used to report results for both types of cameras.

 

Resolution: Canon APS-C

Carl Zeiss Distagon T 35mm f/1.4 shows overall performance that can be considered pretty standard for most (good quality) ultra fast wide angle lenses. The lens is very sharp in the center straight from f/1.4. But like with many other wide angles, quality around borders suffers. This is especially visible at wide aperture levels - at f/1.4 border performance is iffy at best and does not reach acceptable levels until f/2.8. Border quality continues to improve as you stop down further and reaches its peak around f/8. Distagon shows its most balanced results in the f/8-f/11 range, and here it is capable of delivering outstanding 19in and very decent 24in prints. Conclusion? Resolution-wise, Distagon 35mm f/1.4 shows a pretty common for wide angle lenses performance pattern. Obviously that is not a bad thing and the lens delivers pretty solid results from f/2.8. It's just the border quality at f/1.4 that disappoints me - but you've heard this complain from me quite a few times by now.

 

MTF50 (Line Width/Inch on the Print) @ 35mm
MTF50 (Line Width/Inch on the Print) @ 35mm

 

Normalized raw MTF50 @ 35mm
Normalized raw MTF50 @ 35mm

Resolution: Canon FF

The lens showcased a very similar performance on a full frame body ((to performance on an APS-C body that is). Performance in the center was outstanding straight from f/1.4, while border quality lagged, especially at wider aperture levels. At f/1.4 border performance is unimpressive, but quality improves with stopped down aperture and by f/2.8 it reaches a more or less acceptable but still not stellar level. The lens performance peaks around f/8-f/11 where both center and border quality are simply outstanding. Conclusion? Well, what did you really expect here? A miracle? The lens shows consistent results on both APS-C and FF cameras and that counts.

 

Normalized raw MTF50 @ 35mm
Normalized raw MTF50 @ 35mm

 

Chromatic Aberration: Canon APS-C

Chromatic aberration on an APS-C body was somewhat higher then what I hoped to get from a Zeiss lens. CA averaged 1px in the center with wide open aperture, dropping to a more manageable 0.3px by f/2.8. CA around borders was even higher, averaging ~1.3px at f/1.4 and dropping to ~0.8px by f/4.

 

Chromatic Aberration (APS-C) @ 35mm
Chromatic Aberration (APS-C) @ 35mm

Chromatic Aberration: Canon FF

When it comes down to CA, the lens fared somewhat better on a full frame Canon 5D. CA did not exceed ~0.6px in the center. CA around borders averaged ~0.9px at the wider aperture levels (f/1.4 through f/2), but dropped to ~0.5px by f/4 - still quite manageable for a wide angle.

 

Chromatic Aberration (FF) @ 35mm
Chromatic Aberration (FF) @ 35mm

 

Distortion

The lens showed minor degree of barrel distortion - at 0.69% distortion is unlikely to cause any major issues in general photography.

 

Distortion (FF) @ 35mm
Distortion (FF) @ 35mm

 

Vignetting

Vignetting was moderate for a wide angle lens. On a full frame body, Distagon T* 35mm f/1.4 registered light falloff in the range of ~1.1EV at f/1.4 to less then ~0.3EV at f/11, which is not that bad. On an APS-C body, light falloff is even less, ~0.8EV at f/1.4, droping to ~0.2EV by f/5.6 and below.

 

Chart Crops: Canon APS-C

Here are 100% crops taken with an APS-C type Canon Digital Rebel XTi, comparing image borders at f/1.4 and f/8.

Image borders @ 35mm (100% crop): f/1.4 vs f/8
Image borders @ 35mm (100% crop): f/1.4 vs f/8

Chart Crops: Canon FF

Here are 100% crops taken with a FF type Canon 5D, comparing image borders at f/1.4 and f/8.

Image borders @ 35mm (100% crop): f/1.4 vs f/8
Image borders @ 35mm (100% crop): f/1.4 vs f/8