Metabones Speed Booster - Vignetting with Tele-Lenses

The following images are from NEX-7 + MSB + Leica Vario-Elmarit-R 1:2.8-4.5/28-90 ASPH.

FL is 28 mm, f/2.8, OOC JPG, no post processing.

One can clearly see the image quality degradation in the corners.

Next we correct the RAW file for lens distortion, chromatic aberration, and vignetting.

Image quality is obviously suffering in the corners.

Now let's look at a post-processing corrected image that was taken at f/8.

One clearly can see the soft corners.

Now let's stop down to f/22 and only correct for chromatic aberration.

The image appears to be useable.

I also noticed with the MSB that focus is no longer preserved if one focuses for one FL and the changes the FL.  That's a dramatic difference compared to using the lens just with an adapter.

With best regards, K-H.