Article Index

Flare

Flare could be a major plague with this lens for a couple of reasons. Firstly, some of the older samples do not have coating, which means significantly lower resistance against flare. But even the ones that did receive post-manufacturing coating are single-coated and hence are not as effective in blocking strey light as the modern multi-coating. Secondly, even with coated samples, scratches and coating blemishes from the age or abuse would amplify flare as well. If you're not careful and shoot the lens with a light source near or within the picture frame, you're risking of getting a lot of nasty artifacts which could ruin your images, like ones below - notice color shifts, glare, drastically reduced contrast (can it be any lower?), basically the whole bunch of issues that would be rather hard to fix in postprocessing.

 

 

ISO 160, 1/8000, f/2, 50mm

ISO 160, 1/1000, f/8, 50mm

 


Vignetting

Summitar shows moderate amount of vignetting on the APS-H type Leica M8. The lens clocks ~1.5EV at f/2, dropping to ~0.8EV at f/2.8. Light falloff is minimal beyond f/4.

 

 

From practical point of view, light falloff will cause some darkening of corners at f/2 and to a much lesser degree by f/2.8, but should not be noticeable in all but light colored scenery. Either way, if it bothers you, fix it in post-processing (or try coding the lens to let M8/M9 firmware take a stab at it) - if you're using Photoshop, set Vignetting Amount in the Lens Correction menu option to +20 to compensate.

 

Vignetting @ f/2 (Leica M8)

 

Distortion

Summarit showed fairly minimal pincusion distortion - at ~0.7%, distortion is unlikely to be visible in most real life results.