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Help with AF questions (Sony a9) - manual and Sony won't help

Alastair MacLeod

New to TalkEmount
Jan 3, 2019
Hello folks,

I am a new (amateur) user of Sony Alpha having recently sold all my Canon gear and bought a new Sony a9 and three Sony lenses. I love the camera but there are a few things related to the super-smart autofocus capability which the manual is really unclear / unhelpful about.

I have been trying, unsuccessfully, to get some additional support from Sony in terms of getting a better understanding of the workings of the various focus systems and functions. Having now given up, I hope someone or some folks will take the time to look through the below and come back to me with at least some of the answers – even knowing the answer to some might help me unravel the rest.

Thanks in advance,


1. Center Lock-On Autofocus
a. Getting it to work at all!
- There is a setting which appears to be like a “master setting” in Shooting Menu 1 page 5/13 (AF2). When I set this to on, I get a message on the LCD “Object Setting” / “Tracks nearest subject to screen center in ‘o’”. I get the same thing when I set it to on using the default on C4 button which is set to Center Lock-On Autofocus.
- When the above messages appear, I can push the centre button of the control wheel and it locks and then tracks a center object – as, I assume it should.
- However once I have cancelled that by pushing the center button again, there does not appear to be a way to re-enable the Center Lock-On Autofocus without turning it on again.. what I mean is, looking in AF2 (5/13) it is still shown as being set to ‘ON’ however when I push the center button on the control wheel now, nothing happens. The only way to get it to come back on is to turn it on again (either in the menu or by using the custom button C4).. even though it’s saying it’s on.. you need to reconfirm ‘ON’ again.. at which point the tracking option reappears.
- Surely this cannot be the designed behaviour? I expected, if it was turned on, that pressing the center button would start off the center AF tracking but it doesn’t. Only by going back in and turning it on again, THEN pressing the center button. This essentially means a minimum of 3, maybe 4 keypresses before the function is working EACH TIME you want to use it! Rendering it literally worth than useless.
- What am I doing wrong here?!
b. Single shot AF versus continuous
- It appears that this Center Lock-On Autofocus works fine single-shot AF.. I haven’t tried it yet in continuous AF.. does it work in both?
c. Versus Focus Area “Lock-On AF: Expanded Flexible Spot”
- What, if any, is / are the difference(s) between these two apparently very similar functions?
- One thing I do notice is that the Focus Area option “Lock-On AF” does NOT work when the camera is in single shot AF mode. Which is a little weird since clearly these functions are highly similar.. why would one work but the other would not work?

2. Face Recognition vs Eye Recognition
a. Recognition capability versus focus area
- Does the focus area have ANY bearing at all on how the face rec or eye rec works? For example I normally use Expanded Flexible Spot for my focus area.. if face recognition is turned on, will the camera only look for faces at or near the flexible spot?
- If I compose a shot (badly) so I have one face to the right, one face to the left (neither of which covered by the centre spot focus area) and then some high-contrast focusable object in the centre… will the camera choose the left face, the right face, or the non-face high-contrast centre subject?
- Slightly less extreme version of the previous, if I have two faces in the frame but neither covered by the center spot, and assuming there is nothing in the foreground under the center spot (so the camera should figure-out that the faces must be the subject)… will it ignore the centre spot and pick one of the faces? Which face will it pick? The nearest? The highest contrast?
- Again in a world where there are two faces that are different distances from the lens, which face will the camera choose to focus on.. the closest one..? The one with the best contrast?
- Is there a way to “force” / tell the camera which of the two faces that it can see to focus on?
b. Eye Recognition
- Does eye rec work in fundamentally the same way as face rec i.e. compared to my questions above about face rec, would the answers for eye rec be substantially the same (multiple faces, multiple eyes, different distances, not covered by the center spot, etc)?
- Is it correct that eye rec AF will effectively overpower face rec AF?
- Again if there are multiple eyes within the overall frame, is there a way to direct the camera as to which eye to use for the focus point?


TalkEmount All-Pro
Nov 26, 2012
Surrey, UK
Real Name
I struggle with some of this too. I used Mark Galer's youTube videos to set mine up for portrait but still find it quite irritating to watch the focus area keep changing all the time when using face detect/eye detect. Would love to have a clearer view also!

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