Article Index

Flare

To my surprise, Sonnar showed a major weakness against flare. To be fare, all lenses will flare in extreme situations, it's the amount of artifacts that the lens produces in such cases that really counts. The two shots below show how Sonnar performance in one of the more challenging situations, with the sun positioned right above the picture frame on the lens side and the sun rays bouncing off the nearby building before hitting the lens at about 45 degrees. Both shots show fairly low contrast levels, and both showcase noticeable glare as well as color shifts. Nasty...

 

ISO 100, 1/4000, f/1.8, 135mm

ISO 100, 1/250, f/8, 135mm

 

 

Vignetting

The lens registered noticeable, but more or less manageable amount of vignetting on a full frame Sony a850. At f/1.8, the light falloff reaches ~1.1EV, quickly dropping to much lower levels by f/2.8 and from that point, remaining negligible.

From practical perspective, you will see some darkening of corners when shooting light-colored sceneries at widest apertures. Artifact is not particularly distracting and you can easily fix it during postprocessing - set Photoshop's Vignetting Amount in the Lens Correction dialog to +20 to compensate for the falloff. Alternatively, if your camera has built-in vignetting correction, set it to medium level.

 

Vignetting @ f/1.8 - Sony a850

 

Distortion

Sonnar ZA showed negligible amount of pincusion distortion - at ~0.2%, distortion is superficial at worst and will not be visible in real life scenarios.