Canon's release of 600/800mm f11 lenses PROVES you don't need Cannons!

Started 2 months ago | Discussions thread
Dennis Forum Pro • Posts: 19,666
Re: Autofocus performance

Tony Rogers wrote:

Would I be right in saying that an f/11 lens on full frame should have a technically more difficult job focusing with pdaf than an f/5.6 lens on m43?

That's an interesting point ... I don't know much about it other than old rules of thumb that said certain brands needed this speed lens or that speed lens to AF. Canon must know what they're doing, but that doesn't mean that it will be a speed demon or even focus well in low light.

- Dennis
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