Originally posted by GaryH Hey Dan, do you find the AF performance virtually identical (good or bad ) with the Kenko and the Tamron Tc's? I have the Kenko and AF is pretty good with the 60-250 and pretty bad with the DA*300.
Gary, I don't think I've ever used a Kenko TC so I can't really comment on whether there might be a difference. I had always been under the assumption that the 1.4x Tamron and 1.5x Kenko were pretty similar in design and performance.
Just to clarify, the combo of the DA*60-250 + 1.4x wasn't terrible or anything. In fact of all the DA* lenses that I tried the 1.4x on, the DA*60-250 (surprisingly) behaved the best despite the fact that it's a zoom and f/4. I don't have a 1.4x TC anymore (sold my last one recently), but as I recall this is how I would rank the AF performance of the different DA* lenses with the 1.4x TC attached:
best to worst in terms of AF performance: DA*60-250/4, DA*300/4, DA*200/2.8, DA*50-135/2.8
With the 60-250, the AF worked almost normally, although occasionally it would take a second try to lock focus. It was a little slower to find the focus, but again not terrible all things considered. The DA*300 worked ok, but would often require a second try to lock. Manually focusing close and then engaging the AF would help in terms of locking on the first try. The DA*200 was similar to the DA*300, although I felt like the performance was a little less consistent. Not sure why, as the 200 was a full stop faster, but that's just subjectively how I remember it. The DA*50-135 was the worst performer of the bunch and would almost always require a second or third try to lock focus with the 1.4x attached.