The Voigtlander 15mm super wide is a fantastic lens to look at and no-doubt performs like a trooper when matched with a film SLR but is not so great when paired with a Sony A7R. Due to the lens being so close to the sensor even when using an adaptor to E mount it produces a very strong green at the edges.
The first problem I found was with an E mount adaptor the lens did not screw on without being slightly offset. This caused a problem in the small attached hood of the lens was in the frame when I took a photo, I thought a way to get around this would be to use a small rubber circular washer so I could align the lens correctly. That worked great but the extra couple of millimetres travel sent the focus off on the lens. So even when set to infinity pictures where very soft.
This is the first version of the lens and would be ideal because of its price, I paid just over £200. You can get the version 2 and version 3 of this lens and they would work better on the little Sonys but the price is much more, so your defeating the object of getting a super wide lens for you Sony on a cheap budget.
So, instead of the Voigtlander if your after a super wide lens that works 100% for your mirrorless full frame Sony and you want a reasonable price I would choose the Samyang 14mm and the Samyang 12mm fish eye. Both great lenses that I’ve owned and produce sharp photos.