John Francis wrote:
> That's probably because you were pushing the limits of the AF system.
> A small-aperture lens (f5.6?) and a 1.4x teleconverter is f8 - right
> at the edge of the envelope for reliable AF performance. A 2xTC would
> give f11, which is too small an aperture for AF in most circumstances.
>
> My PZ-1p can AF even the heaviest Pentax lenses without any problems.
> I've even used it with the 80-200/2.8 and a Sigma 1.4x autofocus TC.
>
Hi,
What you wrote is absolutely correct. However, I believe you're missing the
point. I can't remember clearly if the AF system hunted or not before
locking on a subject, but the AF motor of that camera --- that is not as
strong as the PZ-1p's, as Todd mentioned earlier --- sounded like as if it
were overloaded, I mean, as if the that lens --- plus teleconverter --- were
too heavy for it. I believe that cannot be caused by excessive hunting of
the AF, but rather by a mechanical issue. If a AF motor is powerful enough,
no matter if focus could not be obtained, it will hunt for a long time, but
wouldn't sound overstressed. That's what I think about it, anyway.
Best,
Eduardo.
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