AF phenomenon on the 70D: Can anyone explain?

Started Dec 18, 2013 | Discussions thread
OP chbaum New Member • Posts: 21
Re: AF phenomenon on the 70D: Can anyone explain?

I think it is, considering the test setup.

I know that the nifty-fifty's AF motor is supposed to be unreliable and slow. But it was NEVER wrong when using a neighboring AF field. That's simply impossible to explain: 50% crap on the middle field, 0% crap with any other field.

Apart from that, I tested my Canon 100 / 2.8 Macro non-IS: Same results at f2.8. And believe me, the neighboring field was tack sharp at that aperture.

I also tested my Sigma 17-50 / 2.8 and got mixed results. It was 0% crap on the neighboring field, but only 30-40% on the middle field. I also didn't want to really comment on the Sigma because in the German forums they instantly grilled me for using a Non-Canon lens for such a test.

Best regards,


 chbaum's gear list:chbaum's gear list
Canon EOS 70D Canon EF 50mm f/1.8 II Canon EF 100-400mm f/4.5-5.6L IS USM Canon EF 100mm f/2.8 Macro USM Sigma 17-50mm F2.8 EX DC OS HSM
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