This is my most honest test with the 35mm adapter, comparing footage captured with and without the 35mm adapter.
The exposure is locked in the beginning. Autoexposure is set towards the end.
There is about 1 stop of light loss. Vignetting and slight chromatic aberration is introduced as a compromise for a shorter and less expensive adapter.
The image with the 35mm adapter is flipped Vertically (but I forgot to flip it Horizontally)
More info: http://www.hv20.com/showthread.php?t=2825