Autofocus not coping (or something else?)

Fairyrose

Fairyrose

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Hello, I’ve taken some pictures yesterday of my son running around in a large water fountain - the type where the water comes spouting out of the ground and kids have fun trying to avoid the bursts of the jets - but still getting very wet in the process :)

I was shooting in continuous mode and had my camera set as follows:

Autofocus. Continuous mode. Tracking/Wide. Face detection mode. Shutter priority set at 1/1000. Camera chose f4 as the appropriate aperture. ISO 400. I was shooting with my Fuji XT20 and 55-200mm 3.5 - 4.8 lens. At about 55mm focal length.

Now, some of my son’s faces are all blurry and I don’t know what the most likely cause is. Is it:

(a) an incontrovertible fact of life that an autofocus cannot handle this kind of situation and I need to get used to my camera’s/ any camera’s limits?

(b) the telephoto lens was the wrong choice of lens?

(c) if so which lens would have been handling this situation better? (Just as a FYI - I’ve also got the 18-55 and the 27mm Fuji’s) .

(d) is the XT20 not capable of dealing with this scenario but another camera might be? (I’m toying with getting the XT3 anyway, and if the consensus on this forum is that the XT3 would have given me pin point sharp images of my son laughing in the fountain I’m off buying one tomorrow!)

(e) any other user error?

Thank you in advance for your consideration. It’s one of these annoying moments when you think you’re going to come home with heaps of lovely pictures only to realise that on closer inspection they’re almost all soft and useless.
 
Could you post some images for us to see what 'blurry' is.

It's highly likely, from your description, it is point a). The AF system of the Fuji is good and it's delivered a reasonable set of results. - however, you start by mentioning that 'some' of the photographs are blurry and then go on to mention 'they're almost all soft and useless' - which is it?

Also - are you a seasoned / experienced action shooter or was this the first type of sport / action you have tried?

In all honesty, even a D5 / 1DXII may struggle to achieve a 100% hit rate in this scenario - regardless of lens / af configuration.
 
I have an X10. an X 20 and X30 and would not expect the focus to keep up in those situations, nor would I expect my XE2 to be able to either.
It is only the latest generation of cameras like the XT3 and XT30 that have that sort of ability. and the top Sony' are better at it still.
Things are improving rapidly, focus wise, with each generation.

However prefocusing as we did in the past has always worked. This involves focusing on a pre-defined point that you know they will pass over, and fire the shutter when they do so. At one time this was the only possibility you had.... and it works. At some stage I will move on to an XT30, for this, and various other advanced abilities.
It is as capable as the XT3 but not as rugged. its hit rate in the situation you describe should be better than 60% spot on. and nearly 100% acceptable.

I am also worried that some of your softness is not camera shake from moving the camera and jabbing at the release, when trying to catch the shot, your action still needs to be smooth.
I
 
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If you were at 55mm on the 55-200, it might be worth trying with the 18-55 at its long end - it's a bit faster so that might make enough difference. Is your X-T's firmware the latest version? That might make a difference too.

When you say that "some" of your son's faces are blurry, what sort of percentage aren't up to scratch? TBH, all you really need is a few nice ones to remember the occasion, any more are just a nice surprise! bonus.
 
I’m not sure if I’m getting the scenario correct- your using wide AF area with face detect hoping the camera can pick out and track their face with water spouts popping up and down probably obsecuring their face?

I like @toohuge said posting up the photos will help especially you you add settings too.

When you say the photos are soft are we talking the whole photo or only your child’s face? Could the camera have decided to focus on another point?
 
I don’t know your camera but I wouldn’t be using CAF, as soon as the water jets go it’s likely to trigger the AF.
 
Nawty said:
I don’t know your camera but I wouldn’t be using CAF, as soon as the water jets go it’s likely to trigger the AF.
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Continuous AF probably isn’t the problem. The child is running around so continuous AF is likely needed. With one shot the child will have likely moved by the time the camera has locked a focus plane. Personally if there is water spouts and running child continous AF and single point would probably be my choice if I was trying to track the child. Sounds like the water spouts are playing havoc with the face tracking. Auto modes such as face detect and eye AF aren’t going to be infallible in every situation. This type of situation isn’t going to nail focus on every photo. I would suggest it’s going to have a very low hit rate (I would be surprised if 3-5% are in focus at best). That’s a guess at present as until we see the photos and settings used it could be something else.
 
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As folk have said, AF systems are still not infallible. Even my D500 has a disappointing keeper rate, actually makes my 'pathetically poor' Pentax K-3 shine in some instances
 
Thank you to everyone for taking the time to give this some thought and reply. I really appreciate it.

I’m afraid that it is a firm principle of mine not to post pictures of my children on social media so I have to do my best to describe the scenario. I think you’ve all got the situation spot on and that the spouting water bursts were playing havoc with the autofocus.

In answer to what some of you asked, whether it’s just the face or the entire child that’s blurry - it’s mainly the face that’s gone soft on the rejects. Of a burst where my son was running in my direction the closer ones tended to be more in focus. Then again, they were also not ones where he was bang in the middle of the jets spouting.....

What had not occurred to me was that perhaps I should have set the autofocus to Continuous and single point (rather than wide/tracking). It’s just that I thought I need the wide tracking for when my son is running around or towards me. Perhaps that is not so?
 
Experiment! In this digital age, we can fire away to our hearts' content and spend no more than time (compared to film times when we were limited [generally] to 39 or so shots before the film was full, at 3 or so FPS and with the costs of D&P on top of the cost of the film).
 
Fairyrose said:
What had not occurred to me was that perhaps I should have set the autofocus to Continuous and single point (rather than wide/tracking).
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Single point will work as long as you keep that point centred on the subject and nothing else gets in the way. If you're in single shot mode and depress the shutter button fully then the camera should fire the shutter as soon as focus is achieved.
 
rob-nikon said:
Continuous AF probably isn’t the problem. The child is running around so continuous AF is likely needed. With one shot the child will have likely moved by the time the camera has locked a focus plane. Personally if there is water spouts and running child continous AF and single point would probably be my choice if I was trying to track the child. Sounds like the water spouts are playing havoc with the face tracking. Auto modes such as face detect and eye AF aren’t going to be infallible in every situation. This type of situation isn’t going to nail focus on every photo. I would suggest it’s going to have a very low hit rate (I would be surprised if 3-5% are in focus at best). That’s a guess at present as until we see the photos and settings used it could be something else.
Click to expand...

I’d probably feather using SAF, knowing that at that moment I activate the shutter it won’t move, but each to their own :)
 
Nawty said:
I’d probably feather using SAF, knowing that at that moment I activate the shutter it won’t move, but each to their own :)
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Your subject will have moved between focus being achieved and the exposure.
That’s why we have continuous AF, it attempts to predict where the subject will be.

I’d guess a hit rate of close to zero using single shot AF on a fast moving subject.
 
Would it not be true that camera motion combined with subject motion could cause blur even at 1/1000? I'm getting blur at 1/250 for walking subjects sometimes, that being said I don't have VR
 
Why not try a smaller aperture? When I used to struggle with fast moving birds, I achieved a better keep rate switching from f5. 6 to f8
 
Were you using continuous high? This can be an issue on many cameras with an erratic subject - it's oft advised to switch to CM or even CL so the camera has that split second more to re-focus between shots. You don't rip off as many, but who needs 100 shots to get one keeper? Maybe try that?
 
Gil and Cagey - thank you both.

To achieve a smaller aperture I could have cranked up the ISO I suppose, good idea - I’ll try that. And Cagey- yes I used continuous high and you may well be right that the camera didn’t have enough time to focus with the running child.
 
Fairyrose said:
I was shooting in continuous mode and had my camera set as follows:

Autofocus. Continuous mode. Tracking/Wide. Face detection mode. Shutter priority set at 1/1000. Camera chose f4 as the appropriate aperture. ISO 400. I was shooting with my Fuji XT20 and 55-200mm 3.5 - 4.8 lens. At about 55mm focal length.
Click to expand...

I've never had a camera that's really good at continuous focus so I'd start with what Terry mentions in post 4 by pre focusing or zone focusing but to give a better chance I'd go for a wider shot, maybe 24 to 35mm f8-11 and setting the focus at an estimated distance.
 
Fairyrose said:
Gil and Cagey - thank you both.

To achieve a smaller aperture I could have cranked up the ISO I suppose, good idea - I’ll try that. And Cagey- yes I used continuous high and you may well be right that the camera didn’t have enough time to focus with the running child.
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How far away were you from your child? Depth of field for a shooting distance of 3m dof would be around 50cm at f4 and 55mm.

It’s sounds like relying on face detect in this situation of water fountains plus running child was too much for the AF system to handle. Try continuous AF single point first, if they doesn’t work then try pre focusing on a area (it’s a hit and miss technique). One thing to consider is the hit rate of in focus images isn’t going to be that high so don’t expect everyone to be nailed perfectly. The good thing with digital you can check focus straight away and make adjustments as required to experiment.
 
In my experience with Fuji tracking, if it locks into the first image, then most if not all the images in the sequence/burst are in focus (CAF + zone tracking)

If it fails to get decent AF on the first image then most if not all the images in the sequence are out of focus

It’s much better at zone focussing when the subject can be predicted, the wide tracking modes are very hit and miss.

It’s also much better at objects coming towards the camera, or slightly offset, than those moving across the field of view, unless you pan as well.
 
Im not sure but I seem to remember seeing face detection tests with many cameras and if I remember the subject needs to be moving fairly slowly and facing the camera quite well for it to work well.
That would explain why it does not work well with a child running about the place perhaps. Don't know for sure though.
 
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