Eduardo wrote:
ECCJ> Another point is the use of teleconverters and extension tubes that are AF
ECCJ> compatible. Due to the adding of couplings, the stress on the motor would
ECCJ> also be increased. Do you agree? Correct me if I'm wrong, but I think the AF
ECCJ> works just like a car transmission or a prop shaft. If you add couplings,
ECCJ> there will be a loss in power reaching its end.
You may be right, as Pentax themselves are reluctant to launch AF
teleconverters. Besides the mechanical coupling issue it may be a
the digital one: the TC must be smart enough to adjust aperture
readings and relay (adjust?) AF data transmitted to the body.
On the bright side, several members here have reported good AF
behaviour with third party AF converters. Specifically I heard about a
well performing combo FA* 200/2.8 - Tamron SP 2x.
Servus, Alin
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