I have a Zeiss 1670. I have had it for more than 8 months. It is the only auto focus and the only zoom lens I have ever purchased. I have been heavily involved in photography since 1962. I bought my first digital, and only digital, a Sony nex-7 in August 2013. I have for a long time been printing in b&w and Ra4. My camewra of choice was a Contax RTSIII. I bought the Sony because of the easy adaption of my lenses and ease of using the due to the electronic view finder. The lenses that I have are 21mm Distagon, 28mm Distagon, 28mm Super Angulon PC, 35mm 2.8 Distagon, 35mm Pc Distagon, 50mm 1.4 Planar, 60mm 1:1 Makro Planar, 100mm Planar, 200mm Apo Sonnar. I print with a Canon 6100 Pro Graf printer and I use Lightroom 4. Mostly I print the full framew about 6.2x9.6 inches on 8 1/2x 11 paper. I have made prints up to 17x25 inches. My adapter is a Kipon which allows 10mm of axial displacement.
I do not consider myself an expert but I certainly have had a longer photo experience than most on this forum.
My criteria for judging a lens is by looking at my prints. I believe tghat the testing provided by Klaus serves a very needed role.
THANK YOU KLAUS!
I have been very happy with all my lenses. The Zeiss 1670 was bought for more handy and quicker usage as well as a wider angle of view.. It has become my most used lens. Sharp enough to cut the mustard for sure.
The FE 24-70mm is certainly not great.