Have initially an old Canon zoom lens tested and found what posting to the boards in the end almost all people: The autofocus is extremely slow and clumsy. Generally it takes some time to focus, however, is at times also a few centimeters behind or in front of the object.
Then I ordered a manual fisheye for Canon because there is not yet something for E-mount. First, I noticed that the focus to infinity is next. Horizon and distant things are out of focus. Through a bit of trial and error, I've found that with maximum focusing distance of 0.3m the lens distant things were sharp. On the Canon of my colleague, the settings of the lens, however, voted properly.
So came the so-called flange in suspicion, which is the distance of the lens to the image sensor in the camera. This is Canon EF 44 mm and Sony E-mount 18 mm, so the adapter must be bridged exactly 26 mm. When remeasuring I realized that the adapter had only 25.6 mm, ie 0.4 mm too little. Sounded to me once very little on. Then I broke the lens and moving it gently minimal bayonet back and forth, and lo and behold, the focus changed.
So was actually the flange of the adapter inaccurate and this small 0.4 mm sufficient to disturb the focus of the lens completely. So I unscrewed the front flange of the adapter and put me washers ago with precisely the lack of 0.4mm. Bingo, now the focus is exactly right.
Conclusion: If you easily do the tinkering, perhaps gets a favorable alternative. Convenient probably go with the expensive products.
