Sigma 2x converter

[billfranklin]

I just tried a Sigma 2x tele extender with my Canon 100mm-300mm ef lens. It absolutely would not focus in auto mode, slow or otherwise. It will focus in manual mode.

It also would not focus with the Canon 35-135 IS or with a Sigma tele auto focus lens.

Is there a solution to this? Has anyone out there been able to use a Sigma 2x converter with these lenses on the D 60?

Appreciate any feedback.

Bill F.

[50/1.4]

You should not be able to AF at apertures smaller than ~ 5.6. If you want to make sure the converter AF's at all, try a faster lens of 2.8. You should be able to AF with a 1.4 or 1.5X at the wide end and then lose the ability as you zoom out. Also, make sure to put
the converter on the lens first, then put the whole assembly on the camera or you may not get AF even with a fast lens. There is a possibility you could get AF from a 2X if you are using an EOS-3 and have lots of light with the resultant f9 since EOS-3's are designed to AF @f8. Good luck.