a6000 Prime Lenses

Started Aug 16, 2014 | Discussions thread
tomtom50 Veteran Member • Posts: 3,244
Re: Yes, the Sigma has PDAF in the center

audiobomber wrote:

tomtom50 wrote:

I don't know about the Touit. I don't have one.

PDAF is more than flashing little squares (which the Sigma has in the center)

And I don't have a Sigma. This is what the Touit does, mounted on an a6000:

In AF-C mode, it shows flashing green squares in the center when Wide area is selected. It will not lock focus in Zone mode. With Wide area and AF-Lock, it will not follow the target. Is the Sigma behaviour the same?

It is how the camera behaves. CDAF shows itself by "shimmering" as the camera passes back and forth over best focus. It shows itself by shimmering every time you acquire focus.

PDAF doesn't jiggle focus the same way. PDAF, if you are in focus, instantly turns green again if you acquire focus without any shimmering.

CDAF, if you are in AF-C, pumps focus like a maniac and cannot track focus well. PDAF does not pump focus and track focus nicely.

How can you track focus if the focus area can't move away from the center?

Ummm. You are tracking action moving on the center area toward or away from the camera?

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