Taping pins on Kenko 1.4x TC does not work

Is the TC you are using the Canon 1.4X in your signature? I am pretty sure it is a reporting TC.

No, I am playing with the Kenko. I do have Canon 1.4x TC, and use it a lot with the 70-200 f/4, but it does not work with the Sigma because Canon TC has a protruding end.

Ok! I guess you have to decide if it is worth playing with. Good luck. Let us know if you figure anything out.

Lbsimon wrote in post #17011337
The lens does AF, but not realibly.

Yup. That is some people's definition of 'working'.

I will test it tomorrow. If no reliable AF, I will do MF, or will sell the thing.

If it doesn't give reliable AF (It almost guaranteed will not on your 120-400), you still might want to keep it. It will allow you to use a 1.4X on all your non-EF-S lenses. Your Canon 1.4X will only work on your 70-200. Though re-looking at your lenses, there is not many you would need a 1.4X on.

I was able to get out of the house today to a local wildlife refuge. Amazingly, in good light the TC's auto-focus was fairly reliable! I was surprised. At the moment I cannot say anything about the IQ, I will download and view the shots later today, but at least I know I can use it on sitting birds.

No, it is definitely not good for birds in flight, but considering that I paid only $80 for it, if the IQ is acceptable, I will keep it.

Looks like the IQ is not that bad! Used with both AF and MF.

https://picasaweb.goog​le.com …y0liipFm0?feat=​directlink
https://picasaweb.goog​le.com …y0liipFm0?feat=​directlink

Both photos are heavily cropped.