I went back and read through your post a couple of times just so I understood the situation.
You currently have the Swaro ATM 65 mm with one of their zooms (wide angle or standard 20-60)?
My initial thoughts are that if you are getting vignetting then it is most likely because either the eye relief is too short on the zoom or the apparent field of view is fairly narrow. Of course it could be that the adapter is too "thick". The way to determine which of these issues is the cause would be whether or not you are getting a sharp black edge to the vignetting. If the edge is sharp then it is likely a narrow apparent field of view. If the edge is fuzzy then it is either the adapter or the eye relief.
With some eyepieces I readily get vignetting from the narrower apparent field of view. Others I don't get anything at all. It also depends on whether or not I am in regular "Photo" mode or I am in "Video" mode. Video mode seems to introduce some zoom into the image without actually using the manual zoom adjust. As a result vignetting is greatly reduced.
In the instances where I do get vignetting in the image I remove it simply by cropping in post-processing.
Hope this helps.
Last edited by FrankD : Monday 4th January 2016 at 17:27.