A9 focus fails

Ziggy99

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Joined
Jan 25, 2019
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262
Location
Australia
The first time I took the camera out I noticed that locks were often hard to come by with small birds. Nothing would get focus.
Some settings experiments and a firmware update later and I'm not seeing any improvement.
The bird can be in mid ground with little around to confuse the AF or it can be closer in amongst foliage with plenty to confuse the AF.
Yesterday for the first time I added the 1.4 TC to the FE200600 and this failure hit a new level. I lost four shots in a row.
I did a simple test: a sapling trunk that was in good light with plenty of contrast. I used Spot: Small, Medium, and Expand Flexible. The AF area was entirely or substantially over the bark.
First up was a failure to focus on anything at all. Then I found with repeated alternating between more distant foliage and the trunk, focus occurred but was slow. I suspect the camera has some ability to learn. I've found similar results with test locks on a horizontal power line - initial failures followed by some success if a nearby object was used to set the range.
Settings: Focus/release balanced; AF sens set at 4.
If this was a DSLR I'd be blowing the AF sensor out or getting it repaired.

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Ziggy99

TalkEmount Veteran
Joined
Jan 25, 2019
Messages
262
Location
Australia
I've done some more testing.

Thom Hogan suggested canting the camera - nope.
Forum members elsewhere suggested putting AF tracking sensitivity on 1 - nope.
A Sony rep suggested Expand Flexible Spot - nope.

Out in the field when it happened again I accidentally hit my BIF settings button and that worked; Tracking Zone. The bird was contrasty enough against the foliage.

I've come across two A7 series users reporting the same problem.
 

Ziggy99

TalkEmount Veteran
Joined
Jan 25, 2019
Messages
262
Location
Australia
Matt Granger in his YouTube review of the FE 400 mentions several instances of complete focus failure during his soccer shoot.

I was out again yesterday trying to focus on a small still bird, in midground and good light, in the centre of the AF area and the frame, and got repeated failures (see a later success below). I'm wondering whether it's worse in firmware 6. In time repeated alternation of subject and distant AF calls seemed to train the AF and get a result, and as before, trying to focus on something nearby and transferring to the subject can work - if there's something nearby (there wasn't here) and the bird hangs around.

This was with the FE 100-400 & 2x TC. That combo worked fine on BIF.

Tracking: Zone worked and I have to test that further with a bird mixed up in foliage. It will depend on subject recognition obviously.

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BIFs no problem

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Ziggy99

TalkEmount Veteran
Joined
Jan 25, 2019
Messages
262
Location
Australia
Here's another couple of tests, partly to add some horizontals into the mix as a line-type sensor should cope better with those.
These are with an AF Spot overlapping a post, wire or branch. A horizontal wire in the second pic didn't fare any better than a vertical.
EXIF showed no point in focus.
100-400 & 1.4 TC. at 560mm. Focus/release: balanced. Focus range: full. The branch was closest and the post was as close as the wires.

Branch on an angle
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The vertical in the middle is a star post about 10m away.
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