Z6 II Eye and face focusing--Sux

Started 5 months ago | Discussions thread
BISCUT Regular Member • Posts: 444
Re: Z6 II Eye and face focusing--Sux

beatboxa wrote:

HRS wrote:

In answer to a request for a sample illustrating my problem--the camera claims it has focused on an eye, but then either focuses on the other eye or on neither:

Image taken at 1/200 sec., f4, with flash. Auto-area AF (people)/AF-C focusing. No other non-default focusing settings.

Claimed Focus Point

Actual Focus Point

Why do you say that the camera claims it has focused on an eye that is not in focus? (To me, the camera doesn't claim it has focused on an eye, but rather placed an AF box where the eye is and focused on something within that box. This distinction is not intuitive / subtle, but very important).

I see high-contrast vertical lines (hairs) that are in focus at that focus point.

As I've said on this site many times, eye-AF is a subject recognition / tracking mechanism and not an autofocus mechanism. Eye-AF tells the camera where to put the AF box, but not how to focus (since the focusing is primarily PDAF-based rather than CDAF-based--and a true "eye-AF" would require at minimum a CDAF trim step).

What happened here was almost certainly that those hairs, being high-contrast (and vertical) are what happened to get focused on. Unfortunately, these things can happen sometimes--it's largely a game of chance. If you want a better guarantee that they won't, use Pinpoint (though obviously then you have to do the "eye recognition & tracking" yourself, which may not be practical).

(BTW, this above scenario can be a challenge as AF algorithms & sensor scans get more & more precise in terms of pixel information...in other words, a lower-resolution PDAF comparison could have missed those hairs and ironically focused correctly. And this is where more sophisticated AF algorithms, including more CDAF, will come into play).

Here are a few writeups I did a while back on this topic:

Well said, Sir.

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