Performance better than expected

Although a loss of image quality with the magnification in all teleconverters is accompanied, the imaging performance of this converter is still very good.
By the way the converter fits naturally also for Sony lenses. It can not all be used, but which also affects Sigma lenses, which also not suitable for the converter. It is not about the port that should always fit, it comes to the "Locations" of the rearmost lens in the lens. The front lens of the converter is, as can be seen in the product picture, a little before and so must the lens to be used the rearmost lens be installed a piece inwardly displaced. Otherwise it can not go along just been mechanically.