So, off to The Camera Store here in Calgary, and I borrowed a Nikon first. It had a hitch in the zoom that was most unpleasant, and was near impossible to focus - live view at f8 had so much depth of field that it was 'why bother' focusing. I worried that the focus shift reported would cause autofocus problems and in fact it did, producing a significantly blurred image.
I tried out the Zeiss - no diff. focusing, using manual focus of course (it isn't an autofocus lens) and focus confirmation in the view finder.
Corners were noticeably soft at f 5.6 but the vast majority of the image (probably 80+% was very sharp.
I tried another Nikon - no hitch but still challenging to focus. This time I did get a good image. Right, back to the Zeiss at f11.
Corners are decent if not wonderful but the rest of the image is great, and we're now talking 95%of the image. Not only that, it's easy to focus, buttery smooth, and feels nice in hand. I bought it and headed over to The Bow to photograph Calgary's newest tall building.
The piece was created by Barcelona-based designer Jaume Plensa. It's a face and here we are looking past the chin to the underside of the nose, with the Bow in the background. Both the building and the sculpture are a superb addition to Calgary. Oh, and the Zeiss 15 is damn fine too.