Struggling with Z8 focus tracking

[SCoombs]

I encounter this problem with wildlife frequently, but doing more sports now it's really becoming a huge problem in costing me a lot of key shots I should be getting and it's giving me a lot of clear examples that I can use to demonstrate and ask about this.

There are at least three ways of tracking a subject with the Z system: Wide area with subject tracking, 3D AF, and dynamic area AF.

Wide area with subject tracking has proven to be the most reliable when it works, but doesn't always work and sometimes isn't right for a situation. If the wide area AF finds a subject, it seems to track it reasonably well. However, I also find it to be the most difficult to use to track a subject in a chaotic environment like sports and it's the mode that most takes control out of my hands and makes me rely on the algorithm identifying a subject, which doesn't always work.

3D AF is supposed to, when used with subject tracking turned off, hang onto a subject based in part on color. Seems like it should be a good option for situations like this, where I want to follow a very distinctly colored subject in an environment with lots of distractions. It's not. It almost always tracks for a few frames and then goes to the background. Note that in this case the 3D tracking had a more solid lock initially then you see here. Just in case anyone is unaware, 3D tracking overrides the camera's A3 setting for focus tracking with lock on.

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Dynamic area modes are in theory a tried and true method. They give a central AF point which is essentially a single point AF and should function as such if you keep the subject under it. There are then a series of "helper points" around the outside so that if the subject briefly moves from the central point, the camera is supposed to maintain focus as long as you it remains at least under the helper points.

In practice, I have found that this doesn't work almost at all, either in real-world-use or in testing. I am shooting in AF-C at 20FPS most of the time and always the very first frame when the central point moves off of the subject the camera immediately refocuses on the background. I have tried every combination of settings in A3: from a quick response to a delated response, steady or erratic, and it behaves exactly the same way regardless: it immediately swaps focus. There is no delay even with A3 set to 5.

Some examples of this follow. Before looking, it's worth a quick note that some people say that the AF point displayed by NX studio is not always the real point that was used, but to that I would say 1) We only have to go off of what we have to go off of, 2) I have been paying very close attention to this lately when in the field and the reported points agree exactly with my first-hand, live experience, 3) this is in AF-C with old-fashioned, non subject-detect AF modes which really should eliminate the vast majority of that concern.

https://flic.kr/p/2qo2GHv

https://flic.kr/p/2qo2GKV

https://flic.kr/p/2qo2GGy

These are a few examples of many, many more where the same thing happens: I'll have the dynamic area AF point on a subject with focus, then the subject moves and the AF point moves off of them for as little as 1/20 of a second up to around 1/2 of a second - and sometimes not even off of them completely, but only partially off of them - and the camera immediately focuses on the background or some other thing. I've also done a lot of this with more controlled testing where I have some subject moving according to my choice rather than trying to follow a bird or a player or something and see the same thing.

Does the setting A3 for adjusting the focus t racking delay make a difference? I already noted that it does not, but I will add some nuance to that now: if I get a subject very large in the frame, there is a difference. If I get something that fills the entire height of the frame, for instance, I can put the main AF point on them and then move so that they're now under a helper point and with A3 set to 1 (quick) it will refocus almost immediately whereas with A3 set to 5 (delayed) there is a very nice, healthy delay before it refocuses. In fact when doing this there is even a nice little indication: the AF point turns briefly from green to red right before it refocuses.

This suggests to me that the problem here is that in some or most of these cases my subject isn't being identified as a subject by the AF which is why it's not operating as expected. I could understand this in some extreme cases with a very small subject, but in a lot of these cases we're talking about subjects which are a pretty reasonable size in the frame or a composition which a photographer might even be specifically trying to achieve. For instance, I have a hard time thinking that something like the below is just not good enough for the system to work right.

What am I missing here?

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[ButlerKid]

Have you consulted Steve's eBook and downloaded the Nikon Setting Guide (Sports AF edition) from HERE ?

 

[dabhand16]

What am I missing here?

FWIW - I shoot a lot of rugby matches for my local team. I started with using my Nikon D810, then D850. Later having been smitten by the Fuji XTs I switched to using my XT-4 when they brought out their 70-300 (100-450). I've now got a Fuji XH-2s and have been using the Fujis for action for some time now.

One common thing with both my Nikon and Fuji systems is that I never used/use any subject recognition or tracking AF modes. I got my best results with a dynamic mode on the Nikons and still use it on the Fujis, but I'm swaying to a large single spot with the Fujis now.

I see a lot of similar issues in here involving the various AF modes, but I always remember Steve saying you have to know which AF mode to use for any given situation, but also when not to use them and go back to basics. I think we are getting too reliant on the fantastic things that the AF systems can do now.

 

[SCoombs]

FWIW - I shoot a lot of rugby matches for my local team. I started with using my Nikon D810, then D850. Later having been smitten by the Fuji XTs I switched to using my XT-4 when they brought out their 70-300 (100-450). I've now got a Fuji XH-2s and have been using the Fujis for action for some time now.

One common thing with both my Nikon and Fuji systems is that I never used/use any subject recognition or tracking AF modes. I got my best results with a dynamic mode on the Nikons and still use it on the Fujis, but I'm swaying to a large single spot with the Fujis now.

I see a lot of similar issues in here involving the various AF modes, but I always remember Steve saying you have to know which AF mode to use for any given situation, but also when not to use them and go back to basics. I think we are getting too reliant on the fantastic things that the AF systems can do now.

The vast majority of this post concerns the dynamic mode not working as described or expected. "Focus tracking" is the terminology Nikon uses for the way that its dynamic focus modes - or even, if I'm not mistaken, its regular single point, operate with moving subjects.

 

[SCoombs]

Have you consulted Steve's eBook and downloaded the Nikon Setting Guide (Sports AF edition) from HERE

My post concerns the fact that the system does not appear to actually operate as described in Nikon's guides or documentation, or as described in any of the work of Steve or others offering advice about using the system.

 

[ajrmd]

My exposure to sports with this camera is rather limited compared to my experience with Canon MILC's. Before I depart on that discussion, might I ask what modes/settings were you using in with the three composite images you posted?

As a general rule, it's a bit harder to AF with MILC's because of the lack of cross type AF sensors. The Canon R1 may change that. Nonetheless, I shot football, soccer, baseball, and swimming with the R3 and had very high keeper rates. My experience with Nikon has been limited to some football/soccer practice. I found that a Wide area S/M, custom, or Dynamic area S to be the best bets and generally, I turn SD off. Wide area with SD off will focus on the closest target so it will have a tendency not to jump to the background. That is not true of Dynamic and SD is off in that mode too.

FWIW, I've never had good luck with 3D for this purpose, though you might. Looking at your images, there are several points worth discussing. With the goalie in the goal, the net provides more contrast than the person, that's why one has to zoom in tighter, and avoid large af areas. The same thing applies to your other images where the subjects are rather small in the scene and other areas offer greater contrast. We look at people in unis and easily recognize them, cameras don't as they generally are not of high contrast.

 

[ButlerKid]

FWIW....Steve, I and others seldom use the dynamic modes.

 

[ajrmd]

Supposedly, Nikon uses thousands of long-axis af points of which some 493 are user selectable on the Z8. Thom Hogan goes into this in more detail in his book. If I remember correctly, the af points are under the green areas of the bayer array, so if you look at the green channel for vertical elements, you'll see why the camera wants to focus on the net rather than the player. This might be an approximation of what the camera detects and why it would want to focus on the the net.

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[SCoombs]

My exposure to sports with this camera is rather limited compared to my experience with Canon MILC's. Before I depart on that discussion, might I ask what modes/settings were you using in with the three composite images you posted?

As I said in the original post, these were using dynamic area AF. In particular, the medium option. In any case, I've used all three of the dynamic area modes with essentially the same results.

As a general rule, it's a bit harder to AF with MILC's because of the lack of cross type AF sensors. The Canon R1 may change that. Nonetheless, I shot football, soccer, baseball, and swimming with the R3 and had very high keeper rates. My experience with Nikon has been limited to some football/soccer practice. I found that a Wide area S/M, custom, or Dynamic area S to be the best bets and generally, I turn SD off. Wide area with SD off will focus on the closest target so it will have a tendency not to jump to the background. That is not true of Dynamic and SD is off in that mode too.

The fact that these modes have closest subject priority is the main reason I find them useless for sports. Sports often if not usually requires trying to hone in on a subject who is surrounded by other, closer objects like the bodies or limbs of other players.

FWIW, I've never had good luck with 3D for this purpose, though you might.

I generally do not use 3D for anything, but showed one example of it failing at what is theoretically its primary strength for the sake of trying to be comprehensive in explaining that I have tried all the options the camera offers.

Looking at your images, there are several points worth discussing. With the goalie in the goal, the net provides more contrast than the person, that's why one has to zoom in tighter, and avoid large af areas. The same thing applies to your other images where the subjects are rather small in the scene and other areas offer greater contrast. We look at people in unis and easily recognize them, cameras don't as they generally are not of high contrast.

Here is the problem I have with this kind of line of thinking: we rarely want a photograph that is simply a subject filling the entire frame without any context. Is the suggestion being made here that the AF system will only work for levels of filling the frame which would amount to something akin to a portrait? That's not what we want in sports photography. For instance, I think this shot could probably be cropped in a little bit, but generally it's very close to a composition that we would actually want. Zoom in and it might be okay, or it might be a much less interesting photo:

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Regardless, as I said in the OP, I can accept AF limitations when subjects are truly small in the frame, but I think several of the examples I've posted show subjects which are a pretty reasonable size at which I'd expect the system to work - and heck, they're about the same size in the frame if not larger than some of the examples Steven has used to talk about the blocked shot response settings.

So yes, if the subject is truly tiny that is one thing, but we aren't really talking about subjects that are truly tiny here, but about subjects that are essentially of a size we might reasonably want in a photo.

 

[JAJohnson]

I don’t shoot sports so know that up front.

I’ve found that Dynamic Area AF worked reasonably well when used with my DSLR cameras. Much less so with mirrorless. Perhaps it’s due to the differences in the two AF detection systems. I’ve disabled the Dynamic Area modes on my Z cameras.

Nikon still has work to do in improving the stickiness of its subject tracking but I’ve seen a great deal of improvement looking back to the initial Z9 firmware. Staying with a specific subject in a chaotic visual environment will always be challenging.

 

[SCoombs]

FWIW....Steve, I and others seldom use the dynamic modes.

I never used them in the past, but I started using them after finding the reliability of the wide area modes in getting what I need to be rather poor.

In particular, they're pretty rough for sports where you either have to use them with subject detection in which case it is nothing other than a very low percentage gamble that it will choose the correct person to focus on, or turn it off and then the closest subject priority of these modes causes massive problems for this use case.

 

[SCoombs]

Supposedly, Nikon uses thousands of long-axis af points of which some 493 are user selectable on the Z8. Thom Hogan goes into this in more detail in his book. If I remember correctly, the af points are under the green areas of the bayer array, so if you look at the green channel for vertical elements, you'll see why the camera wants to focus on the net rather than the player. This might be an approximation of what the camera detects and why it would want to focus on the the net.

View attachment 99434

Okay, but let's be very clear about what we're talking about here: the camera has already focused on the keeper and done so without any hesitation or trouble. I put it on him and press AF-On, and immediately it focuses. It is only when the subject moves that the part of the AF system which is supposed to stay focused on something until a relatively long delay has passed is apparently not doing that and is allowing the system to refocus right away.

Put differently, I can acquire focus on a subject like this almost 100 times out of 100 and the better contrast of the background doesn't confuse it. The AF point is on the subject and it focuses on it like a champ. When the focus point moves off of the subject, even for 1/20 of a second, it lets go in spite of the mode/settings being such that it is supposed to hang on. THAT is the problem.

 

[ajrmd]

Okay, but let's be very clear about what we're talking about here: the camera has already focused on the keeper and done so without any hesitation or trouble. I put it on him and press AF-On, and immediately it focuses. It is only when the subject moves that the part of the AF system which is supposed to stay focused on something until a relatively long delay has passed is apparently not doing that and is allowing the system to refocus right away.

Put differently, I can acquire focus on a subject like this almost 100 times out of 100 and the better contrast of the background doesn't confuse it. The AF point is on the subject and it focuses on it like a champ. When the focus point moves off of the subject, even for 1/20 of a second, it lets go in spite of the mode/settings being such that it is supposed to hang on. THAT is the problem.

I genuinely appreciate your frustrations. So, what you are speaking to is how Nikon maintains AF and that exceeds my expertise. In AF-C the AF system is continuously assessing the scene (120x/sec) looking for areas of contrast. Obviously, from your descriptions it is wandering to areas of higher contrast. Why? You'll have to ask Thom or a Nikon engineer for a better explanation.

Also, let's make sure we're on the same page. Dynamic areas do not default to the nearest subject, whereas Wide areas will. Also Dynamic area does not use SD. This is important and is one of the reasons that I'll use Wide areas with no SD frequently for sports when SD is failing to produce the intended results. Sometimes, it will grab on to the near player and that may or may not be good depending on the circumstance, though it is a useful alternative. I've found the Nikon SD less certain than Canon for sports.

With the latest image you posted, I am not able to determine the AF point though it appears soft and I can't determine whether the DOF is insufficient for the group or if there is some motion artifact as well? Can you clarify?

 

[SCoombs]

I genuinely appreciate your frustrations. So, what you are speaking to is how Nikon maintains AF and that exceeds my expertise. In AF-C the AF system is continuously assessing the scene (120x/sec) looking for areas of contrast. Obviously, from your descriptions it is wandering to areas of higher contrast. Why? You'll have to ask Thom or a Nikon engineer for a better explanation.

Also, let's make sure we're on the same page. Dynamic areas do not default to the nearest subject, whereas Wide areas will. Also Dynamic area does not use SD. This is important and is one of the reasons that I'll use Wide areas with no SD frequently for sports when SD is failing to produce the intended results. Sometimes, it will grab on to the near player and that may or may not be good depending on the circumstance, though it is a useful alternative. I've found the Nikon SD less certain than Canon for sports.

Dynamic area does not use subject detection, but it is supposed to maintain focus for a time on the thing it initially acquires focus on if it moves out from under the primary point as long as that thing remains under a helper points. That is the entire purpose of the mode. Nikon seems to call this "subject tracking with lock on" because the dynamic area modes are supposed to adhere to the setting in A3 - Subject Tracking with Lock On. As noted, if I get a subject very large in the frame, it is clear that it does: dynamic area modes will quickly swap to a new target if A3 is set to 1 (quick) and will stay on the initial target for something like a second or two if A3 is set to 5 (delayed). For subjects which are reasonably sized but not huge (like the photo of #23 blue and #21 white in my OP), it doesn't seem to work, though, which is I suppose the point of this thread.

With the latest image you posted, I am not able to determine the AF point though it appears soft and I can't determine whether the DOF is insufficient for the group or if there is some motion artifact as well? Can you clarify?

Well, to be clear proper focus is the issue under discussion here and so if it wasn't focused properly that wouldn't be surprising, but if you're talking about the photo I think you are I actually think Lightroom did something weird with scaling it when I exported because the actual photo does not look at all soft like it does in the crop I posted here. Here is another attempt at showing what it really looks like:

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I'm actually finding this with lightroom a lot recently: there are certain levels of crop where it just winds up doing weird things to the image and produces a lot of softness even though the same photo exported at a larger size and just zoomed in to the same crop level will look fine.

For what it's worth, this was also taken in Dynamic area small with the primary focus point right on the goalkeeper's elbow. It focused wonderfully because I could keep that primary point on the target. Again, it's the "tracking" of moving subjects that I am having major problems with. Focus acquisition in these situations generally seems fine.

 

[ajrmd]

Thanks for the clarification and reposting. As I mentioned, Dynamic small can yield some good results. I find that using larger Dynamic sizes fail as it tends to grab the more contrasty background. Again, I tend to use Wide S/M, have tried a custom (C1) vertical oriented rectangle which I create based on the setting/FL with SD as my primary AF modes. If the AF is failing, then I either turn SD off or switch to Dynamic small. In the limited deployment (football/soccer) it has generally worked well though again, I've found my Canon gear was easier to navigate and more reliable. YMMV.

FWIW, if you do a search, I've had my share of issues with the Nikon AF for BIF in particular Eagles/Osprey when they strike through a catch. It's something I've still not been able to figure out and have tried a variety of AF modes, settings, etc. It seems that the AF will capture the target as it comes to swoop in for the strike and then it suddenly loses focus for a few frames before the catch through the catch and then it regains capture afterwards. I've tried AA, C1, Wide, SD on/off, increasing/decreasing the blocked shot response, changing the subject motion from smooth to erratic, with no improvement. I've also noticed when shooting small passerines coming towards me that at times the Z8 will have initial subject lock for a few frames and then the AF seems to meander as though the predictive AF algorithm is somehow mis-calculating the subject's speed. <sigh>

 

[SCoombs]

Thanks for the clarification and reposting. As I mentioned, Dynamic small can yield some good results. I find that using larger Dynamic sizes fail as it tends to grab the more contrasty background. Again, I tend to use Wide S/M, have tried a custom (C1) vertical oriented rectangle which I create based on the setting/FL with SD as my primary AF modes. If the AF is failing, then I either turn SD off or switch to Dynamic small. In the limited deployment (football/soccer) it has generally worked well though again, I've found my Canon gear was easier to navigate and more reliable. YMMV.

FWIW, if you do a search, I've had my share of issues with the Nikon AF for BIF in particular Eagles/Osprey when they strike through a catch. It's something I've still not been able to figure out and have tried a variety of AF modes, settings, etc. It seems that the AF will capture the target as it comes to swoop in for the strike and then it suddenly loses focus for a few frames before the catch through the catch and then it regains capture afterwards. I've tried AA, C1, Wide, SD on/off, increasing/decreasing the blocked shot response, changing the subject motion from smooth to erratic, with no improvement. I've also noticed when shooting small passerines coming towards me that at times the Z8 will have initial subject lock for a few frames and then the AF seems to meander as though the predictive AF algorithm is somehow mis-calculating the subject's speed. <sigh>

As I said, the problem I have with subject detection modes is that they leave a lot up to chance in terms of what the camera decides to focus on and it can be very difficult with multiple players in close quarters 2-dimensional (but not necessarily 3 dimensional) quarters to make sure the camera is focused on the right thing.

I also find that it tends to do this, where it just drops the subject without me having anything I could have done differently.

https://flic.kr/p/2qoaQQ5

 

[SCoombs]

For what it's worth, since so many people have suggested wide area modes with subject detection I went out this afternoon and did some more experimenting with it. As I said, I've tried it a lot in the past, but went ahead and gave it another look.


The biggest problem with it, especially if we're talking about the very narrow boxes intended to isolate specific subjects in a crowded field, is that as soon as the box is off of the subject it is letting go and focusing on the background. This is the same issue as I have described with dynamic area, but at least dynamic area is specifically designed, theoretically, to give a margin of error where it stay on the subject while you get the point back on if it drifts off.


With the wide area modes there is no margin of error: it releases immediately every time unless the subject is at literal "corporate headshot" levels of filling the frame. Auto area AF can help with this if there is only one subject in the frame - otherwise it's not that helpful.


Obviously there is an element of skill involved here and I'm not looking for something that gives perfect shots when I make mistakes, but there is a reason that camera systems have had options to give a small margin of error for decades now and there's a reason it's posing big challenges when the systems aren't actually doing that.

 

[MartyD]

I shoot a lot of sports but I haven't used the dynamic areas much. I will offer a few comments.

The issue that I question is what setting a3: Focus Tracking with Lock-On actually does. Nikon states that this controls how quickly focus responds if something passes between the subject and the camera when using AF-C. This works fine if a player moves between you and your subject in a sequence of frames. I don't think it has any impact if the subject moves out of the focus area.

I think the dynamic areas might work well when shooting a single subject over a consistent background. I also question how dynamic focus determines what it should focus on. Is it color aware or distance aware? What comes to mind for me is a bird against a sky, seems like a easy situation for dynamic to recognize when the focus distance changed in the center point but is now consistent with what is in one of the helper points. I guess that I have always believed that the dynamic areas worked well for isolated subjects against distance backgrounds.

Are you using back button focus? It looks like at times that the 3D tracking isn't tracking anything at all. I have had issues when just using 3D tracking with being certain that I was on the subject when I initiated the 3D tracking. In some situations I will use subject detection and then handoff to 3D tracking and that has worked well.

In the first image pair that was shot with 3D tracking the camera tracked the post behind the player. I don't know if the first shot you posted was the first shot in the sequence but with the player's arm being the only part of the player in the focus area I could see how the camera would get confused and stay with the post and not with the player especially at that distance.

In the second and third set of images I would expect subject detection to work very well. I have not had subject detection fail me in this type of situation.

Using a 70-200 when shooting soccer certainly provides a challenge for face/eye detection and even dynamic areas If the subject is larger in the frame the face/eye detection has worked very well for me. I have found it will pick up the eye of a softball player wearing sunglasses under a helmet and track it pretty well.

I use multiple focus modes when shooting a sporting event. I use subject detection with wide custom C1 and C2 set to dimensions depending on the sport and my shooting location and I adjust them as necessary. I have a button programmed to cycle AF area mode and use Auto, C1, C2 and 3D. I also have a button programmed to handoff to 3D tracking when necessary.

Sorry I didn't answer your question about why dynamic doesn't work well for sports, I don't know that there is a really good answer. I just try to find the focus mode or combination of focus modes that works best for me.

 

[ajrmd]

As I said, the problem I have with subject detection modes is that they leave a lot up to chance in terms of what the camera decides to focus on and it can be very difficult with multiple players in close quarters 2-dimensional (but not necessarily 3 dimensional) quarters to make sure the camera is focused on the right thing.

I also find that it tends to do this, where it just drops the subject without me having anything I could have done differently.

https://flic.kr/p/2qoaQQ5

So the latest image appears to be shot in AA and you appear quite far from the subject. I'm not sure if SD really picked up the person or what it is doing. For the first couple of images it stays on the side of the head and then the AF box is larger on the face and the image is OOF.

By comparison, what I described, with the Osprey/Eagles is presented below. It's a long sequence of nearly 100 shots tracking the bird as it dives to the water. All of the initial images are in focus, it tracks well down right near the water and then it loses AF (in spite of the af point remaining on target and the bird is relatively large in the frame) for around 7 images as it goes through the strike and eventually it regains focus. So, I feel your pain!

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[SCoombs]

So the latest image appears to be shot in AA and you appear quite far from the subject. I'm not sure if SD really picked up the person or what it is doing. For the first couple of images it stays on the side of the head and then the AF box is larger on the face and the image is OOF.

By comparison, what I described, with the Osprey/Eagles is presented below. It's a long sequence of nearly 100 shots tracking the bird as it dives to the water. All of the initial images are in focus, it tracks well down right near the water and then it loses AF (in spite of the af point remaining on target and the bird is relatively large in the frame) for around 7 images as it goes through the strike and eventually it regains focus. So, I feel your pain!

View attachment 99498View attachment 99499

I don't really think that the subject in your osprey shots is substantially smaller than the subjects in some of my examples. For what it is worth, your showing much better performance than I see with birds a lot of the time: your subject detection is on the eye/head! I can count on one hand the number of times its gone to the head of birds in flight for me, even with birds that fill up almost the entire frame. It usually just goes to the wing and I get out of focus heads.

In any case, I have to object to the idea (not only from you, but others) that some of these more moderate shots are too small. For instance, here is the entire frame of that shot where the auto-area started to drop off of the subject. Really, if the system can't focus in on a subject this size, then what the heck are we even doing with it? Yes, there are subjects that are too small, but this really is not so small that it should be something the system can't focus on.

What's worse is that as often happens when I raise a question like this I'm now getting (between this and another forum where I posted) people arguing from both sides here: some are saying, "that's too small for dynamic area, use subject detect!" while others say, "that's too small for subject detect, use a different mode!"

The bottom line for me is that this really isn't so small that I shouldn't expect to be able to focus on it without a massive hassle.

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[SCoombs]

I shoot a lot of sports but I haven't used the dynamic areas much. I will offer a few comments.

The issue that I question is what setting a3: Focus Tracking with Lock-On actually does. Nikon states that this controls how quickly focus responds if something passes between the subject and the camera when using AF-C. This works fine if a player moves between you and your subject in a sequence of frames. I don't think it has any impact if the subject moves out of the focus area.

For what it is worth, I have experimented and can see a very clear response from the a3 setting with subjects that are "corporate headshot" size. With big subjects and a3 set to 1, dynamic area will very quickly refocus on the background if I move the point so that only the helper points are over the subject, but with a3 set to 5 and doing the same thing, it will hang on for about a second and a half to two seconds before refocusing on the background. It's very consistent with subjects of this size.

That having been said, regardless of whether or not a3 makes a difference here, the whole purpose of the dynamic area modes and the helper points is to help maintain focus in the kinds of situations being discussed here.

I think the dynamic areas might work well when shooting a single subject over a consistent background. I also question how dynamic focus determines what it should focus on. Is it color aware or distance aware? What comes to mind for me is a bird against a sky, seems like a easy situation for dynamic to recognize when the focus distance changed in the center point but is now consistent with what is in one of the helper points. I guess that I have always believed that the dynamic areas worked well for isolated subjects against distance backgrounds.

I could be wrong, but my understanding has been that dynamic area modes are supposed to operate exactly like single point but with the addition of the helper points to maintain focus when the single point drifts a bit. As I have understood it from all I've looked at about these modes, going back to DSLR days and through to the Z system, the idea is that they allow you to focus with the precision of single point while giving a margin of error more akin to a mode like the group area AF on the late model DSLRs or the wide area modes on Z.

Are you using back button focus? It looks like at times that the 3D tracking isn't tracking anything at all. I have had issues when just using 3D tracking with being certain that I was on the subject when I initiated the 3D tracking. In some situations I will use subject detection and then handoff to 3D tracking and that has worked well.

Yes always BBF.

In the first image pair that was shot with 3D tracking the camera tracked the post behind the player. I don't know if the first shot you posted was the first shot in the sequence but with the player's arm being the only part of the player in the focus area I could see how the camera would get confused and stay with the post and not with the player especially at that distance.

No, I don't think this was the first shot in the sequence. I forget why I chose to post that. I think I was just looking for one that was closer in sqeuence to the second OOF shot.

In the second and third set of images I would expect subject detection to work very well. I have not had subject detection fail me in this type of situation.

One of the reasons I first started using dynamic area modes is that I have found subject detection to fail in these situations. I posted one example of this a few posts up.

Using a 70-200 when shooting soccer certainly provides a challenge for face/eye detection and even dynamic areas If the subject is larger in the frame the face/eye detection has worked very well for me. I have found it will pick up the eye of a softball player wearing sunglasses under a helmet and track it pretty well.

As I said above, I think one of the issues here is that not every shot is supposed to be a closeup. There are times - and maybe even a majority of the time - when you want a slightly wider field of view to give context to a shot. I am not really finding much difficulty with closeups. It's these sort of shots where you want two or three players full body with a little "room for them to run" in the image that I am having problems getting the camera to maintain focus.

Also, there's always the need to have a little extra room in the frame to make sure you don't miss a shot because some unexpected movement takes something like the ball or a limb out of a super tightly cropped frame.

I use multiple focus modes when shooting a sporting event. I use subject detection with wide custom C1 and C2 set to dimensions depending on the sport and my shooting location and I adjust them as necessary. I have a button programmed to cycle AF area mode and use Auto, C1, C2 and 3D. I also have a button programmed to handoff to 3D tracking when necessary.

Sorry I didn't answer your question about why dynamic doesn't work well for sports, I don't know that there is a really good answer. I just try to find the focus mode or combination of focus modes that works best for me.

 

[SCoombs]

Something I have discovered in some testing this afternoon:

If the subject moves out from under the main point slowly or if the camera moves slowly so that the helper points stay on the subject, it seems to keep focus. If the subject moves quickly, even if it stays under the helper points, it refocuses on the background.

So, if I follow a walking player and briefly lose him, the helper points keep focus on him. A goalkeeper or other player quickly darting, even if I keep the helper points on in the very same way, causes a loss of focus. I now also wonder if there is any way that this related to ajrmd's issues with diving birds.

 

[Lance B]

Why using a 70-200 f2.8 may not be helping in your scenario, I just think you're trying to use a too short a lens for the subject distance. The pitfalls of shorter glass and thinking it is better than longer glass:

The Fast Glass TRAP - Don't Make This Mistake!

Think your F/2.8 lens is always the best choice for wildlife photography? Think again. In my latest video, I’m uncovering common mistakes many photographers make when reaching for that fast glass. Wait until we get into Depth of Field and ISO - it's shocking how most photographers get this...

bcgforums.com

 

[SCoombs]

Why using a 70-200 f2.8 may not be helping in your scenario, I just think you're trying to use a too short a lens for the subject distance. The pitfalls of shorter glass and thinking it is better than longer glass:

The Fast Glass TRAP - Don't Make This Mistake!

Think your F/2.8 lens is always the best choice for wildlife photography? Think again. In my latest video, I’m uncovering common mistakes many photographers make when reaching for that fast glass. Wait until we get into Depth of Field and ISO - it's shocking how most photographers get this...

bcgforums.com

I appreciate the thought here, but the reality is that I have tried my 180-600 for these sports and I stopped using it because even with very significant crops on the 70-200, I was getting much better results simply from the difference in noise level of 2.8 vs 5.6/6.3. Even with modern denoising, it wasn't really remotely close. Yes, on a bright sunny day the 180-600 gave me some good results, but a lot of these HS sports right now are taking place in October evenings as the sun goes down without any lights. I'd post some examples, but I deleted most of the results from the 180-600 because they just didn't clean up well enough to be usable whereas the 70-200 shots cropped in from 200mm to 600 mm FoV just looked much better.

Edited to add: I wonder if it just comes down to a difference between human beings vs. wildlife. I have always been pretty happy with modern denoising on wildlife photos, but on human subjects it's more hit or miss whether or not I like it. This may simply be that we are more attuned to the small details with human beings and so we are more sensitive when they're lost because they're overpowered by noise.

In any case, the problems I am describing are not ones that I would really attribute to this problem. As I said in a post above, not everything is supposed to be a close up. I like this shot (which was done with the 180-600 as there was some light available at this time):

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But I like this one much, much more:

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If I can get more reliable focus tracking when shooting things that look like the first shot, that's great and all, but if that is really just a way of saying that I can't get reliable focus tracking for shots closer to the second, that's not so great - especially since we're talking about sports here and so shooting a bit more zoomed out than one wants the final product is usually a good idea to avoid losing a key shot because some difficult to predict movement leads to stuff getting missed or cut off. After all, the most interesting and exciting moments to capture often involve someone doing something very unexpected to make a great play, the ball bouncing in some unexpected way, etc.

 

[Lance B]

You need to watch the video I linked to. If you are doing significant crops, then you are losing isolation and gaining noise. If it is just small crops you may not notice the loss of isolation or noise, but significant crops you will. Watch the video, it is all explained and demonstrated. A cropped 70-200 to 400mm will be the same DOF as a 400mm f5.6 lens and have the same noise as double your ISO. There is no getting around this.

I would never use my 70-200 f2.8 over my 180-600 for birding (unless it was in a cage or VERY tame!) as it wouldn't be able to pick up the bird's eye for a start, but the resultant crop would be worse. That is the very reason *why* these longer lenses exist, in order to make focusing easier, to make the resultant image IQ better. If you are looking for better IQ at that distance, then you need to invest in a better lens like a 400 f2.8TC, this is the price you pay for wanting great IQ and focal length. Using a 70-200 f2.8 in order to try to achieve this is destined to fail.