Metabones Speed Booster - Vignetting with Tele-Lenses

Here is another shot with the same configuration:

Sony NEX-7 + METABONES L/R - E mount Speed Booster + Leica APO-Telyt-R 1:3.4/180

Again, shot wide open at nominally f/3.4 but effectively at f/2.4, ISO=4000, and at 1/60s.

I used Hand-held Twilight mode.

One can still detect some vignetting and image degradation in the extreme corners.

But to me the image certainly appears to be usable.

With best regards, K-H.