a1: AF-C priority selection

[turtle1300]

I have a Z5, and I've noticed that shooting my kids, the autofocus really struggles when they're running (or even walking slowly) toward the camera within about 15 feet. I realized I had AF-C priority selection set to "Focus Priority". I set it to "Shutter Priority" thinking I'll get fewer misses when the camera is not taking time to check focus before the shot (as the kids continue moving). I'll check this later if my oldest agrees to help.

Generally been trying to specify a focus point to increase hit rate, and hoping the new priority selection helps.

Anyone else have any input here?

Also possible the camera just can't track f/4 lenses that fast within 15 feet and if that's the case, so be it.

 

[SoCalAngler]

I have a Z5, and I've noticed that shooting my kids, the autofocus really struggles when they're running (or even walking slowly) toward the camera within about 15 feet. I realized I had AF-C priority selection set to "Focus Priority". I set it to "Shutter Priority" thinking I'll get fewer misses when the camera is not taking time to check focus before the shot.

Generally been trying to specify a focus point to increase hit rate, and hoping the new priority selection helps.

Anyone else have any input here?

Also possible the camera just can't track f/4 lenses that fast within 15 feet and if that's the case, so be it.

I have a Z5. Setting to Shutter Priority may help. I did this with my Nikon DSLRs too.

An yes the closer the subject is the more difficulty the camera has with subjects moving towards the camera.

I have a small white dog, which due to the color provides some challenges. To get the best images of the dog coming at me I do the following (it has worked for children too):

Get out of Auto Area focus mode with subject detection. The Auto Area mode with or without subject detection seems to be a bit slower in my experience than the other modes. Same with subject tracking. I use Dynamic or Wide Area Small or single point. You will have to maintain the focus point on your subject though. Use the largest that will still allow the subject to fill the focus box.

I set Custom Setting #a3 (Blocked Shot AF response) to a lower value than the default of 3. Try 2 or 1 and see if this helps. This setting is usually used when you are panning with a subject and want the camera to try to maintain focus on the subject if something else (a light post, another player in a sport, etc) temporarily comes between the camera and the subject and would trigger a large change in focus.

If you set this value to a lower number the camera seems adjusts focus a bit faster. At least with my Z5 I get better results with oncoming people and animals at closer distances and in continuous shooting modes just as I did with my D7XXX bodies. Using a lower value for setting a3 may or may not help - It's worth trying. If you are trying to capture an image of a child moving around in a group where another may come between you and your camera you probably want to leave this at the default though.

Also, if I can acquire focus on the subject for a fraction of a second before I press the shutter button I get better results. I have my camera set up for back button focus. So I am acquiring the subject and initiating focus before depressing the shutter button. I understand that with children you often do not have time to set up for the burst though.

I usually capture running pets or children at f/5.6 or f/8 when they are close and bump ISO. The tiny bit of extra depth of field can sometimes help with an image with a small focus miss still be usable (viewed on phone, social media, reduced size for web, 4x6 print, etc).

I love my Z5. It is a great value for general photography. But as you have seen one of it's weaknesses with the AF system with faster action, or even moderate action really close, especially when the target is moving right at you or nearly so (we used to call this situation constant bearing, decreasing range).

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If cameras and lenses can have autofocus then why can't I?

 

[turtle1300]

Thanks for the very detailed response!

I did set priority to shutter, and I changed the blocked shot option from the default 3 to 2.

I think it helped, the camera was able track my son on his scooter at 120mm f/4 to within about 12 feet, beyond which I couldn't track/keep up with him.

Any idea if the Expeed 7 cameras are better in this regard, or is there a fundamental limitation considering the magnitude of element movement required to affect focus at this distance?

 

[SoCalAngler]

Thanks for the very detailed response!

I did set priority to shutter, and I changed the blocked shot option from the default 3 to 2.

I think it helped, the camera was able track my son on his scooter at 120mm f/4 to within about 12 feet, beyond which I couldn't track/keep up with him.

Any idea if the Expeed 7 cameras are better in this regard, or is there a fundamental limitation considering the magnitude of element movement required to affect focus at this distance?

I think a greater movement of the lens elements is required to move the focal plane as a subject gets closer. When I look at the distance markings on my manual lenses I can see that at closer distances the focus ring needs to be turning through a greater arc. For example, I have one 50mm lens on my desk now that requires more than twice the rotation to change focus from 4 to 3 feet as it from 30 to 15 feet.

I would expect that an Expeed 7 body my be able make the calculations quicker but it still needs to move the glass. I don't have one to try.

There are a couple of options I will try if I need to. One is to get farther away and use a longer focal length lens. The other is to use a wider angle lens, which typically requires a smaller movement of the glass elements, and then crop the image.

 

[mosswings]

I have a Z5, and I've noticed that shooting my kids, the autofocus really struggles when they're running (or even walking slowly) toward the camera within about 15 feet. I realized I had AF-C priority selection set to "Focus Priority". I set it to "Shutter Priority" thinking I'll get fewer misses when the camera is not taking time to check focus before the shot (as the kids continue moving). I'll check this later if my oldest agrees to help.

Generally been trying to specify a focus point to increase hit rate, and hoping the new priority selection helps.

Anyone else have any input here?

Also possible the camera just can't track f/4 lenses that fast within 15 feet and if that's the case, so be it.

Long ago I made the mistake of trying to capture my dog's face while they ran towards me from 15 yards or so with my DSLR, no slouch in tracking, with focus priority set to "focus". Every shot was just slightly off, because the camera took just that much longer to acquire focus...by which time my dog had run out of the zone of focus. Lesson: use release focus priority and practice precise tracking - if the burst rate is fast enough, you'll get some keepers. But remember, a subject running directly towards the camera is the hardest kind of motion for the camera's AF to track.

Advanced cameras have focus+release priority options to deal with this problem by combining behaviors - first shot focus priority, subsequent shots release priority.

 

[Ruedon]

Thanks for the very detailed response!

I did set priority to shutter, and I changed the blocked shot option from the default 3 to 2.

I think it helped, the camera was able track my son on his scooter at 120mm f/4 to within about 12 feet, beyond which I couldn't track/keep up with him.

Any idea if the Expeed 7 cameras are better in this regard, or is there a fundamental limitation considering the magnitude of element movement required to affect focus at this distance?

Expeed 7 (re)introduces 3D AF-C tracking into mirrorless cameras. It extrapolates (predicts) the movement while focusing. This works very well with my D500 and thanks to subject and eye recognition even better with my Z8. I'm always configuring focus priority for the first release and shutter priority afterwards.

The autofocus of mirrorless cameras also benefits from faster sensor readout. The Z5II coming with a faster sensor and Expeed 7 should improve a lot, compared to the Z5 regarding tracking performance.