I bought 2 X Mark III extender on ebay to use with a 300mm f2.8 II (which I haven't bought yet) and tried it out on my 5dMarkIII and 7dMarkII with my 70-200mm f2.8 lens. No autofocus at any aperture. I checked the autofocus on the lens and it was on. Did I make a mistake in my assumptions that it would work on these cameras? or is something wrong with the extender. I use my 1.4 extender and it works fine. The 2X extender looks immaculate with everything clean and the sensors bright and shiny. Any ideas would be appreciated.
Extender EF 2X III Help
- Thread starter westr70
- Start date
Return to seller for a refund. If he will not honor the return, hopefully the transaction qualified for buyer protection from eBay.
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westr70 said:
Return to the seller and buy a used one from B&H or Adorama. They guarantee everything works.
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You should have no issue returning it to the seller, but you might have to pay return postage.
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Does aperture control actually work? If so, autofocus ought to work, because it uses the same communication pins. You might check your camera's AF settings to make sure it is set to continue searching upon a focus miss.
Failing that, the TC might be decentered or something.
Failing that, the TC might be decentered or something.
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