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2X APO Teleconvert



I recently purchased a 2x apo teleconverter for use with my 200mm APO lens. It seems to work fine except for the fact that the autofocus has trouble locking on. It will get very close to a sharp focus and then pulse in and out of focus. The aperture is 5.6 so the AF should work. Does anyone know what the problem is?
What brand tele did you buy? Minolta made two 200 f/2.8 lenses. One in 1986 called the Minolta AF 200 f/2.8 APO and in 1986 Minolta AF 200 f/2.8 HS-APO G. The HS lens has faster focus capabilities compared to the other.
To stop that pulse in and out of focus simply your focus to "lock" on the camera and you will get much better results.