Canon Extender EF 1.4x III Review -

larry wrote:

" I've dropped a star because of the decision by Canon to cripple the AF with some cameras and not others and because the RRP is slightly too high IMO."

You down-rated the *extender* because of physical limitations on lower-end Canon *cameras*. I realize this is because you don't understand the limits of AF modules, but the down-rating is not a fault of the extender.

Not at all. It's not because of the limitations of "lower end cameras" but because of Canon's conscious decision to cripple the use of this adapter on some cameras but not others.  The fact that some users have reported success... having taped over the contacts to prevent the Extender from reporting back to the camera... proves they can be used on models that it was not intended to be used for. I mounted one to a telescope last night and though the shot was framed and the camera instructed to "release shutter without a lens present", the Extender kept telling the camera to shut off.
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The general consensus from experienced photographers is that "Canon intentionally cripples the use of extenders" - presumably to influence camera migration to higher-end models.  Feel free to conduct your own online research and you'll find that my opinion on this matter is repeated by many others.  Having been a licensed Canon dealer years ago, I can assure you that this comes as no surprise to me. The punishment of withholding a star because Canon shrewdly chose to penalize anyone without a Pro-Camera (yes, Canon only make ONE model of Pro camera) seems entirely fair to me.