AI Servo mode - learnt a lesson - no focus and recompose

I always use one shot focus mode with centre focus point. Few days back went on safari at national park here and first time used AI Servo mode. Back at hotel reviewed pictures and wow learned this tough lesson... can not focus and recompose as it focuses where you press shutter
So what settings would you do when faced with stationary or slow moving wild life and you would like to recompose. Assumption... you are in a jeep and driver stops for a few seconds for you to click and there is not enough time to change focus point away from centre focus point.

if you use all of the focus points, you can set the camera to start focus using the center point ... once the camera locks on using the center point, you should be able to recompose (servo focus) and the focus dots should stay locked on to the original subject.

many people use back button focus and servo mode as well

ssmanak wrote in post #18572587
I always use one shot focus mode with centre focus point. Few days back went on safari at national park here and first time used AI Servo mode. Back at hotel reviewed pictures and wow learned this tough lesson... can not focus and recompose as it focuses where you press shutter
So what settings would you do when faced with stationary or slow moving wild life and you would like to recompose. Assumption... you are in a jeep and driver stops for a few seconds for you to click and there is not enough time to change focus point away from centre focus point.

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AI Servo is definitely the right mode to use. . However, when using AI Servo, most successful wildlife photographers use back button focusing. . They also change the focus point so that they can put the animal where it is supposed to be in the frame.

Recomposing is really not a very good way to do things if you can put the animal in the right place instead. . In fact, I have never heard of any accomplished wildlife or bird photographer who makes a habit of recomposing. . The good photographers don't just use center point - they select the correct point, and then continually change points as the subject moves or as the scene changes.

So, to sum it up, use AI Servo focusing mode, with back button focusing enabled and the shutter button disabled (from focusing duties). . Then choose the correct autofocus point manually depending on where you want the animal to be in the composition. . Only recompose when there is no AF point that covers the part of the frame that you want the subject to be in, and even then, do so as slightly as possible, using the closest possible AF point (not the center one).


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ssmanak wrote in post #18572587
I always use one shot focus mode with centre focus point. Few days back went on safari at national park here and first time used AI Servo mode. Back at hotel reviewed pictures and wow learned this tough lesson... can not focus and recompose as it focuses where you press shutter
So what settings would you do when faced with stationary or slow moving wild life and you would like to recompose. Assumption... you are in a jeep and driver stops for a few seconds for you to click and there is not enough time to change focus point away from centre focus point.

Quick answer: set up back button focus.

Rod

With the 6DII, I would not be using the center point only.

As long as the subject is the closest thing under the focus points, it should stay in focus.

If needed, shoot wide and crop to the desired framing.

Thanks folks.. will try out following two techniques using AI Servo mode...
1. Select all focus point and select manual adjustment of centre focus point
2. Select back button for focus and disable shutter release button from focus duty...

Happy shooting ..

kmilo wrote in post #18572590
if you use all of the focus points, you can set the camera to start focus using the center point ... once the camera locks on using the center point, you should be able to recompose (servo focus) and the focus dots should stay locked on to the original subject.

many people use back button focus and servo mode as well

When using AI Servo you can't lock the focus. That's the point of it. One way of handling this issue is to take AF off the shutter button, use back button focus and take your finger off the button before recomposing.

yes, i said "locks on" ... meaning acquires a subject to track .... rather than "lock" meaning getting to a spot and staying there forever

I agree with everything you've said otherwise

mwsilver wrote in post #18578164
When using AI Servo you can't lock the focus. That's the point of it. One way of handling this issue is to take AF off the shutter button, use back button focus and take your finger off the button before recomposing.

Tom Reichner wrote in post #18572591
In fact, I have never heard of any accomplished wildlife or bird photographer who makes a habit of recomposing. . The good photographers don't just use center point - they select the correct point, and then continually change points as the subject moves or as the scene changes.

Changing focus points as an animal moves? Seriously? Unless you're shooting elephants milling around a watering hole, you wouldn't possibly have time to track a moving animal and try to keep up with it while moving focus points around. I can imagine trying to do that with birds in flight.

ssmanak wrote in post #18573393
Thanks folks.. will try out following two techniques using AI Servo mode...
1. Select all focus point and select manual adjustment of centre focus point
2. Select back button for focus and disable shutter release button from focus duty...

Happy shooting ..

Back button af is your strongest solution here; however, in response to your original post/description, if you are forced (by time) to stick to center point only, stick the af point on your subject's eye or as close to as you can get and zoom out/frame loosely so you can crop to correct position later.

I think you're going to find that #1 is a difficult way to go about things, however. I would avoid All AF points and just expanded or zone AF for your initial starting point. It takes some practice on tracking moving subjects, but I just never see All points work out correctly. It always grabs *something* that I don't care about in the frame instead of the thing I'm trying to focus on.

One Shot with stationary animals is fine, which is something called out in the OP. If you half press the shutter, then hold it down while you recompose, then press the rest of the way, nothing is going to refocus. Or as others call out, move focus off the shutter button and to the back of the camera.

One more question I have due to the situation at hand, what were the shutter speeds on these shots? The problem might be two-fold, focus, recompose, then refocus caused issues, but also perhaps the shutter speed was too slow?

saea501 wrote in post #18578205
Changing focus points as an animal moves? Seriously? Unless you're shooting elephants milling around a watering hole, you wouldn't possibly have time to track a moving animal and try to keep up with it while moving focus points around. I can imagine trying to do that with birds in flight.

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Yes, seriously.

There are many times that the animals and birds are "milling about", as you say. . In fact, most of the times I am shooting wildlife or birds they are doing just that.

In these situations, every time a subject turns its head, there is a need to re-focus, using a different focus point.

If a duck is standing there on the ice, with its head looking toward my left, then I need to use a focus point on the right side of the frame, so that it has a lot more space out in front of its head than it does behind its head. . Then as soon as the duck turns his head and looks over to my right, I have to rapidly change the selected focus point to one on the left side of the frame. . Every time an animal turns its head and looks in a different direction, there is a need to quickly change the focus point, so that the composition is placing the animal on the 'correct' side of the frame.

The same is true when animals are gamboling, or walking to and fro as they feed or interact with others.

You also mention birds in flight. . Yes, the focus points must be changed while they are flying.

This time of year I shoot a lot at a heron & cormorant rookery. . The herons and cormorants are continually flying to the rookery and away from the rookery, to and from all different directions. . When a heron in flight appears, off in the distance, and is approaching the rookery to land in the treetops, I need to change the focus point based on the direction that it is coming from, so as to position the bird in the frame so that it has more room (sky) out in front of it than it does behind it. . They come in to the rookery from all different directions, so I don't know what focus point I should use until I actually see the next approaching bird in flight, and then I select the point while it is in the air.

Continually changing focus points for moving animals and flying birds is really a pretty simple process; I'm not sure why you seemed to think I wasn't being serious. . I certainly don't want to be one of "those" photographers who always has the animal in the center of the frame ...... so of course I'm going to move the focus points around in unison with the animals' movements.


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I suspect many of us are reach limited, so we are going to crop the animal down anyways, and can recompose during post. I would rather use the best AF points I can on any given camera and then crop out accordingly. Also many birds are much smaller and faster, which means they are changing direction quite a bit, and it would be impossible to keep moving AF points around as they are darting about.

Finches, cardinals, blue jays, and other like birds just won't make it a very enjoyable experience if one had to change the AF point all the time. This is where a zone AF approach may come in more handy, and then again, you aren't changing the AF point, the camera will start on one inside the zone, and then take over from there.

If one isn't reach limited and they can fill a good portion of the frame with the bird, then yes, cropped recomposure is less useful.

Finally, most wildlife shots are more of a portrait style where the final result has the creature is in the center of the frame.

TeamSpeed wrote in post #18578243
One Shot with stationary animals is fine, which is something called out in the OP. If you half press the shutter, then hold it down while you recompose, then press the rest of the way, nothing is going to refocus.

Right, it won't refocus. . But, the act of recomposing can still throw your focus off a wee wee bit.

Why? . Because the focus plane is actually more planar than it is spherical. . So if you recompose you may be throwing your focus off by a few inches.

I know that if something is 120 feet away, missing focus by three or four inches doesn't sound like it would be a big deal .... but it actually is a big deal because then the eye will not be the absolutely sharpest part of the animal. . When you constantly pixel peep and want to printing photos at 48" or 60" across, this stuff matters. . If you are not that demanding, or if you print at more normal sizes, then recomposing in such situations will be okay.


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Tom Reichner wrote in post #18586182
Right, it won't refocus. . But, the act of recomposing can still throw your focus off a wee wee bit.

Why? . Because the focus plane is actually more planar than it is spherical. . So if you recompose you may be throwing your focus off by a few inches.

I know that if something is 120 feet away, missing focus by three or four inches doesn't sound like it would be a big deal .... but it actually is a big deal because then the eye will not be the absolutely sharpest part of the animal. . When you constantly pixel peep and want to printing photos at 48" or 60" across, this stuff matters. . If you are not that demanding, or if you print at more normal sizes, then recomposing in such situations will be okay.

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I would suspect the crowd that is printing at 48 and 60" is QUITE small. Also, usually DOF is several inches, if not a couple of feet (for those of us not invested in very fast long lenses), so recomposure just from center to 1/5 of the frame off center doesn't create that large of a shift in the focal plane placement, unless the subject is very far out and then we are back to being reach limited.

I am also saying that I doubt that with moving wildlife there is alot of recomposure going on. With static subjects, perhaps, but not with moving targets. The composition will change during the post processing.