Focusing Problems on Water

[pochito]

I am a beginner. I started to practise "tracking" BiFs not long ago.
For this I chose a reservoir with lots of birds, among them plenty of seagulls flying. Somebody recommended tracking seagulls as a first step.
I can (more or less well) track them.
The problem seems to be that the background is the water. I shoot from an (not much) elevated position but most of the time my camera prefers to focus on the small waves behind than on the bird.
I use a D810 w an 600mm zoom. Mostly at 600mm.
I tried Dynamic Area w 21 points, with which I can keep the birds inside the area most of the time, but my AF seems to AVOID the birds, I even made a desperate attempt with Automatic, since I expect the gulls to be nearer, to no avail :-(
I understand that "Group" should focus on the nearer subject but it looks like a small area to practise "tracking".
I'm shooting at 5 fr/sec 1/2500sec
Any tipps? Thanks in advance.

 

[realspeed]

Are you using continuous focus? and continuous with lock on? caqn't say what it is in the menu as my D810 is in for repair

 

[DRwyoming]

I understand that "Group" should focus on the nearer subject but it looks like a small area to practise "tracking".

The Group area isn't quite as small as it looks. I've been pleasantly surprised a few times when a small and fast bird comes into view and Group AF just grabs it when I'm not right on top of the bird at the start. I view the area outline for Group as the center of the area but not the total size of the area the way it is in the Dynamic Area modes. For clear shooting venues without a lot of closer high contrast objects to create a false lock, Group works really well for me. I'd give that a try.

 

[gordon_g]

What @realspeed said also have to checked to see if the lens is focusing properly where you want it to and not front focused or back focused? Also as mentioned Group focus is larger than you think and when I use it I put the bird in the middle of the 4 focus boxes. Was there enough light when you were shooting? Maybe the camera could not get a good lock?

 

[Warren D]

I've had and continue to have the same problem from time to time. The AF seems to prefer the water and it gets worse the farther the bird is from you, ie, the smaller it is in the viewfinder. The best solution is the least do-able, get closer and get the bird bigger in the frame. You also can't go by the AF sensors as they are outlined in the VF as the actual sensor points rarely line up with the VF indicators. Most of mine are a little high and to the right of the position shown. The D810 is a decent camera and at the time the AF was considered good but times have changed and the AF system is a little slow by current standards. Take a look at your lock on settings, on my D4 and D810 I found it best to turn that feature off. (OK, turn lock on---off. Something sounds odd, like hitting the Start button to shut down your PC!)
I've found for birds on the water that either single point or 9 point dynamic does the best. If you're lens has stabilization it can twitch the image around (you may even see movement of the entire frame in the VF) and that can throw the AF point off your subject if you're shooting a burst.

 

[pochito]

Thank you for the prompt responses!

Realspeed: I use Lock-On at the OFF position. Yes, continuous focus
DRW: OK. I'lll try it tomorrow (if it's not raining Tks
Gordon: I have "Fine Tuned" the lens for 600mm at a distance of 15m using Dot Tune. If I did it properly..., that's another matter
I'll re-check that.
Light was OK, nice Autumn around midday
I used 1/2500 f/9.0 (manual) Variable ISO (around 1600/1800 in these cases)
I got a red dot (small rectangle) on the focus point most of the time.
Warren: Lock On OFF. Haha Yes I have it OFF
Yes, I've stabilization ON. Maybe it's not that important at that shutter speed?

 

[DRwyoming]

Any tipps?

The only other thing I'd ask is how large the Gulls were in your frame?

The smaller the subject in your frame, the harder tracking will be. Yes, Gulls can be good subjects for learning how to track, part of that premise is that they're relatively large in the frame. If they're way out across the water they'll be a lot more challenging from an AF acquisition and tracking standpoint. It's not always easy to find larger and slower flying birds like Herons, Egrets, Cranes, Swans and the like but those are some of the easiest subjects when you're first trying to track BIF partly because they're larger but they also because they tend to fly more steadily and slower and glide into landings.

If possible I advise folks to start BIF photography with bigger slower birds first, moving to something like Hawks and Eagles which aren't too tough and then maybe to Gulls and similar birds and finally to smaller more erratic birds like Swallows and Flycatchers which can be really tough. But for practice sake, Gulls are a pretty good IF you can get them pretty large in the frame.

I'd also say starting your tracking practice with a 600mm lens can be more challenging than starting with a wider angle lens. Again you want to be close enough to keep your subjects relatively large in the frame but if you can find a place where you can do that while shooting at something like 300mm or 400mm you'll likely find tracking easier than with the larger lens that can be hard to even find the bird in the viewfinder.

From the standpoint of getting close for larger subject size and for possibly shooting with a bit wider angle lens it really helps to find places where birds are very accustomed to people or even where folks frequently feed the birds so they come in close. Fishing piers, some beaches, city ponds and other places are good places to find Gulls and other birds that aren't skittish around people and tend to come in close.

 

[EricBowles]

The D810 had the first generation of Group AF mode. It did not work as effectively as the same mode in the D500, D5, and D850 - or Wide modes on the Z cameras. The big failure is it was inconsistent in using Nearest Subject Priority in Group mode. But - Dynamic AF was more forgiving than the later cameras and tended to use a bit more of the group of sensors. Later cameras required you to return the subject to the AF point in Dynamic - and there was quite an uproar at the time.

The miss with Dynamic is usually you pick up the background. The reality is you need to work on technique. If you can, try to continue using Dynamic and testing Group to see if you can find situations where it does work. Generally you are talking about percentages or degrees of success and failure - it's not black and white. The longer you can keep the AF point on the subject, the better it locks onto contrasty areas, so framing and focusing early is helpful.

As far as settings are concerned, shoot your lens wide open or stopped down a half stop - not at f/9. You need the light. Keep your shutter speed at 1/2000 or higher - 1/2500 is good for flight. Turn off any kind of VR or stabilization at 1/500 or faster shutter speeds. It may not matter, but it can hurt your image.

AF Fine tuning may help, but it needs to be under similar conditions and distance. I would not worry about a fine tuning issue if you are missing the target completely. Fine tuning corrects small errors that show up on every image - not missed focus.

 

[pochito]

Thank you DR and Eric for the VERY interesting advice.
BTW the largest gull, incoming view, is from tip to tip of the extended wings about 1/3 of the frame. Most are much smaller. I'll take this observation into account.

 

[gbodave]

Your problem pochito is the very reason I always use single point AF for wildlife with any target big, small, moving, flying or static. I don't want to trust the camera. I know where I want the focus point to be and I make sure it's in that place.

 

[Woodpecker]

I am a beginner. I started to practise "tracking" BiFs not long ago.
For this I chose a reservoir with lots of birds, among them plenty of seagulls flying. Somebody recommended tracking seagulls as a first step.
I can (more or less well) track them.
The problem seems to be that the background is the water. I shoot from an (not much) elevated position but most of the time my camera prefers to focus on the small waves behind than on the bird.
I use a D810 w an 600mm zoom. Mostly at 600mm.
I tried Dynamic Area w 21 points, with which I can keep the birds inside the area most of the time, but my AF seems to AVOID the birds, I even made a desperate attempt with Automatic, since I expect the gulls to be nearer, to no avail :-(
I understand that "Group" should focus on the nearer subject but it looks like a small area to practise "tracking".
I'm shooting at 5 fr/sec 1/2500sec
Any tipps? Thanks in advance.

Once you got your subject focused once and you use AF-C the cameras are usually really good in tracking holding on to the subject as long as you can keep it in the range covered by the selected number of AF sensors (D9, D51, ...) The problem you have might be caused by the fact that depending on your movement (handholding, panning) or the bird moving (flying, bird moving up and down due to little waves) you loose your subject out of this area. Then your camera will look for something else to focus on within the area covered by the AF sensors. If that is a nice contrasty spot on the water behind or in front of your subject, that's it. There's one thing you could try, if you are able to focus on "your bird" o.k. in the first place and then loose focus on it while trying to keep it in the AF area.

The option is called AF Lock-On and is used to prevent the camera from immediate refocusing when sudden changes in focus distance occur. As described by @Steve in his AF book this option can help when tracking a bird that is suddenly passing behind a tree. Without AF Lock-On the camera will immediately focus on the tree putting you at rist not to find the bird back after reappearing at the other side of the tree. The same can happen, when a bird on the water is moving down or up due to little waves. It disappears from your AF area and the camera would immediately try to focus on the best it can find in the AF area. If the change in the focussing distance is big enough, AF-Lockon would become activated, holds the focus where it was when the bird moved out of the AF area for a period of time that is adjustable in a certain range.

It is not a set and forget option though. I am using BBAF all the time and usually combined that with AF-C in D9 as my default with the option of activating D51 temporarily via the buttons on the front barrel of my 500mm lenses. In situations where I know I am after a subject in a surrouding where it would be easy to loose focus and the lens then would try to focus one somthing in a very different distance or even start to pump, I activate AF Lock-On with a medium to long time. That's why I have put the AF-Lockon setting in "My menu".

 

[gbodave]

AF lock on isn't wholly accurate in that there is no precise setting that will ensure 100% success so for me it's as hit and miss as dynamic AF.

 

[Woodpecker]

AF lock on isn't wholly accurate in that there is no precise setting that will ensure 100% success so for me it's as hit and miss as dynamic AF.

Well, it was more of a proposal to the pesrons starting the thread about something (s)he could try. People that are so far down the road that they are looking for 100% success probably have found out for themselves already what is the best way to deal with that kind of problem. That said, as I can see that you are shooting Sony. I don't know this system, but I would expect that even if functions are called the same across manufacturers they most likely don't work exactly the same way.

Beside that we all know that having 100% of whatever you are aiming for in this world is an illusion anyway .

 

[gbodave]

No hidden meaning in my comment, just stating what my experience has been. All suggestions are welcome. I only moved to Sony a couple of months ago and was with Nikon for years, The principle is the same.

In fact the Sony Guru recommends the Sony version of multi point dynamic AF and it's just appalling. For it to work properly you need a subject that fills the frame with absolutely nothing else that could be a distraction. It will often grab anything but the subject and oddly enough on that day I was photographing birds on water - waste of time. I was at the same place yesterday using single point AF. A much better experience..

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[pochito]

Then your camera will look for something else to focus on within the area covered by the AF sensors. If that is a nice contrasty spot on the water behind or in front of your subject, that's it. There's one thing you could try, if you are able to focus on "your bird" o.k. in the first place and then loose focus on it while trying to keep it in the AF area.

I chose 21 points because that is an area where I can (more or less) keep a flying gull inside.
Single point or 9 would need some more practice.
I could try to refocus when I notice or feel that the bird abandons the area. I'm using BBAF and once in focus I seldom let it go. I mean I press it continuously during the tracking.

The option is called AF Lock-On and is used to prevent the camera from immediate refocusing when sudden changes in focus distance occur. As described by @Steve in his AF book this option can help when tracking a bird that is suddenly passing behind a tree. Without AF Lock-On the camera will immediately focus on the tree putting you at rist not to find the bird back after reappearing at the other side of the tree. The same can happen, when a bird on the water is moving down or up due to little waves. It disappears from your AF area and the camera would immediately try to focus on the best it can find in the AF area. If the change in the focussing distance is big enough, AF-Lockon would become activated, holds the focus where it was when the bird moved out of the AF area for a period of time that is adjustable in a certain range.

It is not a set and forget option though. I am using BBAF all the time and usually combined that with AF-C in D9 as my default with the option of activating D51 temporarily via the buttons on the front barrel of my 500mm lenses. In situations where I know I am after a subject in a surrouding where it would be easy to loose focus and the lens then would try to focus one somthing in a very different distance or even start to pump, I activate AF Lock-On with a medium to long time. That's why I have put the AF-Lockon setting in "My menu".

I have lock ON in the OFF position. As I understand it the lens would not try to focus on anything else at all.
Maybe I'm mistaken? Again, I'm a newbie .

 

[DRwyoming]

I have lock ON in the OFF position. As I understand it the lens would not try to focus on anything else at all.
Maybe I'm mistaken? Again, I'm a newbie .

Yeah, AF-LOCK ON with a moderate time setting should help you in the situation you described. When you turn AF-LOCK ON to the OFF position the AF system will rapidly switch from one high contrast area to another as soon as it sees a potentially better AF target within the Dynamic AF Area selected. With AF-LOCK On enabled, once you have acquired focus and are tracking it will hold onto that same focus target a bit longer before jumping to other high contrast targets within your Dynamic AF Area. The longer you set the time constant of the AF-LOCK-On the longer it will hold onto the currently tracked target before looking for other potential high contrast targets.

So in your situation where the Dynamic AF Area is fairly large (21 points) and you're panning past water with ripples or waves that are somewhat high contrast you'd ideally like the AF system to hang onto the Gull you're tracking for a bit longer before jumping to alternative targets like the ripples/waves. I wouldn't set the time constant crazy long as then it can also make it harder to jump back onto the Gull when the camera does grab the wrong target but a mid time setting may help you.

The situation where you'd want a very short hold time in your AF-LOCK-ON settings or perhaps even turning it all the way off is when you have many choices of targets and may want to jump quickly from one bird to another while AF is still activated. So if the Gulls are swarming and you want to quickly jump from one to another in mid air while still holding in the AF activation button then a short time constant or turning OFF the AF-LOCK-ON feature can help but that's not really the best situation to start learning how to pan and track BIF as it's a bit more advanced to track and rapidly switch subjects on the fly. When first learning, pick one subject more or less clear of others and work on tracking and panning with that single bird. In that situation a bit of focus hold time via the AF-LOCK-ON feature can help.

I'd say you're also seeing the downside to using a larger Dynamic AF Area. Sure it's easier to keep at least some of a 21 point area over your fast flying subject but that also means there are a lot more focus points that are not on your subject and can grab focus on other high contrast elements in your scene. A smaller area like D9 may be harder to keep over your subject if you do keep it on your subject there are fewer outer focus points to grab onto some kind of background high contrast area like the water. It's all tradeoffs but as you get better with panning and tracking and anticipating the way your subjects will fly it will become easier to use a smaller Dynamic Area.

One other tip, shoot some images but when first learning to track flying subjects it can help to just track with AF and not release the shutter a lot. IOW, spend more time working on the tracking and less time capturing images at the start as it's easier to track without mirror blackout time. Sure in the end we want to capture images so you'll still probably shoot quite a bit but spend more time working on the tracking at the start until that part gets easier.

 

[pochito]

Yeah, AF-LOCK ON with a moderate time setting should help you in the situation you described. When you turn AF-LOCK ON to the OFF position the AF system will rapidly switch from one high contrast area to another as soon as it sees a potentially better AF target within the Dynamic AF Area selected. With AF-LOCK On enabled, once you have acquired focus and are tracking it will hold onto that same focus target a bit longer before jumping to other high contrast targets within your Dynamic AF Area. The longer you set the time constant of the AF-LOCK-On the longer it will hold onto the currently tracked target before looking for other potential high contrast targets.

Ouch. I got it really wrong...

So in your situation where the Dynamic AF Area is fairly large (21 points) and you're panning past water with ripples or waves that are somewhat high contrast you'd ideally like the AF system to hang onto the Gull you're tracking for a bit longer before jumping to alternative targets like the ripples/waves. I wouldn't set the time constant crazy long as then it can also make it harder to jump back onto the Gull when the camera does grab the wrong target but a mid time setting may help you.

The situation where you'd want a very short hold time in your AF-LOCK-ON settings or perhaps even turning it all the way off is when you have many choices of targets and may want to jump quickly from one bird to another while AF is still activated. So if the Gulls are swarming and you want to quickly jump from one to another in mid air while still holding in the AF activation button then a short time constant or turning OFF the AF-LOCK-ON feature can help but that's not really the best situation to start learning how to pan and track BIF as it's a bit more advanced to track and rapidly switch subjects on the fly. When first learning, pick one subject more or less clear of others and work on tracking and panning with that single bird. In that situation a bit of focus hold time via the AF-LOCK-ON feature can help.

I'd say you're also seeing the downside to using a larger Dynamic AF Area. Sure it's easier to keep at least some of a 21 point area over your fast flying subject but that also means there are a lot more focus points that are not on your subject and can grab focus on other high contrast elements in your scene. A smaller area like D9 may be harder to keep over your subject if you do keep it on your subject there are fewer outer focus points to grab onto some kind of background high contrast area like the water. It's all tradeoffs but as you get better with panning and tracking and anticipating the way your subjects will fly it will become easier to use a smaller Dynamic Area.

One other tip, shoot some images but when first learning to track flying subjects it can help to just track with AF and not release the shutter a lot. IOW, spend more time working on the tracking and less time capturing images at the start as it's easier to track without mirror blackout time. Sure in the end we want to capture images so you'll still probably shoot quite a bit but spend more time working on the tracking at the start until that part gets easier.

Your advice is really sound. And the explanations very clear.
I appreciate it DRW

 

[Woodpecker]

I have lock ON in the OFF position. As I understand it the lens would not try to focus on anything else at all.
Maybe I'm mistaken? Again, I'm a newbie .

If your have AF Lock-On = OFF this means the camera tries to grab another focus point immediately, i.e. without a delay. If you want to try it out, just set the AF Lock-On to long and AF-C with a single AF sensor. I you now focus on something that is a bit isolated, i.e. a fence post or a traffic sign, the camera will try to keep focus on your target. If you now move the AF field away from your target without deactivating the AF, you will realize a slight delay between moving away from the original target and fpcusing on "something else" that the AF sensor sees. The shorter you set AF Lock-On the smaller the delay gets and if you set it to OFF it is set to zero.

BTW, I agree with @gbodave: The best way not to get cheated by your AF system if to be on AF-C single point. However, if you have a subject moving too erractically or you are in a situation where it is difficult to keep steady or you simply haven't got the right technique (yet) to have a good hit rate with single point AF-C extending the AF sensor area can help, but then you depend on the logic in your camera and even today this logic is quite different compared to human logic, becuse it is always cmbined with intuition .

 

[Woodpecker]

No hidden meaning in my comment, just stating what my experience has been. All suggestions are welcome. I only moved to Sony a couple of months ago and was with Nikon for years, The principle is the same.

In fact the Sony Guru recommends the Sony version of multi point dynamic AF and it's just appalling. For it to work properly you need a subject that fills the frame with absolutely nothing else that could be a distraction. It will often grab anything but the subject and oddly enough on that day I was photographing birds on water - waste of time. I was at the same place yesterday using single point AF. A much better experience..

Sorr,y I didn't expect any hidden meaning behind your post. May be I just got it a bit wrong because I am not writing in my native language.

Apart form that it is interesting to read from a person actually went away from Nikon completely (?), a step where @Steve mentioned that he is at least is thinking about it, if Nikon doens't catch up with mirrorless.

Also good to know that form an experienced shooters's perspectice the similarities between the AF system seem to be bigger than I thought.

 

[gbodave]

It's no problem. I just try and state what my own experience has been. I do a lot of things differently from the mainstream but if it works, it works.

My step away away from Nikon was just about my own situation. I'd been with a D750 for three years and was using a Sigma 150-600mm Sport. I just felt that I couldn't wait for a Nikon mirrorless camera that I would be happy with. New cameras would keep increasing in price and my present gear would keep losing value.

As it happens I got much more on trade in prices than I expected so I came away with a Sony A7R3 and a 200-600mm lens for £1500. I think I got a good deal.

 

[Woodpecker]

It's no problem. I just try and state what my own experience has been. I do a lot of things differently from the mainstream but if it works, it works.

My step away away from Nikon was just about my own situation. I'd been with a D750 for three years and was using a Sigma 150-600mm Sport. I just felt that I couldn't wait for a Nikon mirrorless camera that I would be happy with. New cameras would keep increasing in price and my present gear would keep losing value.

As it happens I got much more on trade in prices than I expected so I came away with a Sony A7R3 and a 200-600mm lens for £1500. I think I got a good deal.

Sounds like it - and a wise decision for you as well. One thing being hard to admit for me is that sometimes following a feeling helps to make better decisions .

 

[pochito]

If your have AF Lock-On = OFF this means the camera tries to grab another focus point immediately, i.e. without a delay. If you want to try it out, just set the AF Lock-On to long and AF-C with a single AF sensor. I you now focus on something that is a bit isolated, i.e. a fence post or a traffic sign, the camera will try to keep focus on your target. If you now move the AF field away from your target without deactivating the AF, you will realize a slight delay between moving away from the original target and fpcusing on "something else" that the AF sensor sees. The shorter you set AF Lock-On the smaller the delay gets and if you set it to OFF it is set to zero.

BTW, I agree with @gbodave: The best way not to get cheated by your AF system if to be on AF-C single point. However, if you have a subject moving too erractically or you are in a situation where it is difficult to keep steady or you simply haven't got the right technique (yet) to have a good hit rate with single point AF-C extending the AF sensor area can help, but then you depend on the logic in your camera and even today this logic is quite different compared to human logic, becuse it is always cmbined with intuition .

Thank you. Yes it seems that I'd got it wrong and used OFF :-(
Today I tried w/ AF LockOn at 3. Maybe because of that the pictures looked now better (see my "sequel" somewhere else in this forum)
I'll try out your test as well.
As for using single point, I think that it will need some more practice. For the moment it's not that easy (for me) to keep those birds in the 9 point area