Quote Originally Posted by Sean Setters View Post
Not too long ago we switched lighting systems for the test chart. We previously used Canon Speedlites set to TTL; now we use Flashpoint XPLOR 600PROs which are also set to TTL. We haven't completed enough tests with the new lights to be confident that they light the chart evenly each and every time. Therefore, the vignetting tests (to be published soon) will be a more precise indication of vignetting performance.
Looks like the III indeed has slightly more vignetting than the II.

https://www.the-digital-picture.com/...9&LensComp=741

Granted, 0.2 to 0.3 in the corners is pretty inconsequential.