Hi. I read so many different views on the combination. Everything from low light to not "locking on" at 300mm. Does anyone use this setup and does it work? If not then you are saving me 250 Euro so thanks in advance 
I need this work on a regular basis and not depending on certain factors.
On the Kenko site it specifies "With the PRO 300 1.4x, DGX full AF operation is possible with camera lenses having a maximum aperture of F4 or brighter. The same light and contrast requirements apply." Does this mean that from over 200mm you have to use manual focus?
On the compatibility list it states that the lens is supported and does not mention the aperture. I wonder also if it is slow on focusing on moving objects.
I need this work on a regular basis and not depending on certain factors.
On the Kenko site it specifies "With the PRO 300 1.4x, DGX full AF operation is possible with camera lenses having a maximum aperture of F4 or brighter. The same light and contrast requirements apply." Does this mean that from over 200mm you have to use manual focus?
On the compatibility list it states that the lens is supported and does not mention the aperture. I wonder also if it is slow on focusing on moving objects.