forpetessake: One more thing nobody mentioned. NEX sensors (esp NEX-7) don't like light falling at acute angles, it results in vignetting and color fringing already a problem with EF lenses. This adapter will contribute even more to this problem, so I wonder if anything but telephoto lenses will be usable at all.
The white paper says "Another nice benefit of the Speed Booster is that it moves the exit pupil further from the image plane for any objective lens. In other words, it actually improves the telecentricity of the lens system. This helps to improve corner illumination and reduce sensor artifacts such as color variations caused by pixel crosstalk."
So it should actually be better.
Beckler8: The extra controls for vertical shooting aren't needed. Why is a rectangular sensor still being used? Switch to a square sensor and either crop later, or in-camera with viewfinder masks, or whenever. Square also obviously captures more of the image from the lens--info. that is lost for no reason. Any possible reason not to do this, other than a slightly bigger sensor? (Though not necessarily). I don't think so, other than lack of thought.
And the mirror would have to be bigger, causing it to hit the back of many(?) lenses.
DSLR shot of a medium format slide taken with my Fisheye66 camera (17mm Takumar lens mounted on a 6x6 camera body).
All the bent lines in this shot remind me of an MC Escher drawing.
I'm sure the lacquer looks very nice in real life.