100-400IS+1.4x(AF works!)

Started Jul 20, 2001 | Discussions thread
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Fred Miranda Senior Member • Posts: 2,469
100-400IS+1.4x(AF works!)

Hi all,

I just got my 100-400IS back from service today and would like to share how to make auto focus work when using the 1.4x teleconverter.

I took the advice of making a few adjustments to the 1.4x teleconverter and now Auto-focus is possible.

It's very simple. Just place a small transparent piece of tape on the last 3 pins of the teleconverter. For more info see here:

On the above link, it’s explained how to modify the Canon TC 1.4x, but I did the same with my Kenko 1.4x PRO 300 and it works like a charm.
I'm sure AF won't be as fast and hunt more but it's better than no AF.

I've tested inside my house tonight and it locked pretty quickly even in low light.

I don't see any side effects. If you want the TC to be like before, just remove the piece of tape. It's that simple.

--Check my photo gallery at:

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