Tough time with AI-Servo, tracking on my 5D3 5DIII

I was outside playing "fetch" - really just trying to test out my new to me camera. And it seems like every single picture is OOF despite being "locked in." I have the AF system on Case 4, and the dog is mostly running towards me with the ball. What can I do to fix this (including my skills).

IMAGE LINK: https://flic.kr/p/qhri​PY

Following the rule of ruling out the simple stuff first, are you experienced with using AI servo?

Why I ask, it is very easy to put it in servo and try to shoot like you have it in one shot focus mode. The solution is to hold down the shutter or even better, hold down the back focus button for a second or so before taking the photo. The servo modes track the subject. To do that it has to be activated for a short period before you actually take the photo. I know this from experience and even though I know it, I still often make the mistake of trying to take the photo too soon.

Another cheap trick to solve this problem is to put the camera in high speed mode and take two or three photos. The first may be out of focus, but the second and third should be fine. I have a neuromuscular disorder and often do that just because I know if the first shot is OOF, usually the second is not. And with any fast action shot, you often need to take more than one anyway to capture just the right moment.

Shutter speed could be a touch slow. It looks (from the small photo) like the focal plane is somewhere near the right place. Try bumping the shutter speed.

Yes, maybe the focal plane is a tad short of the target. Does this lens focus properly on things that don't move?

apersson850 wrote in post #17353826
Yes, maybe the focal plane is a tad short of the target. Does this lens focus properly on things that don't move?

I'm definitely no expert on AI - Servo, but shooting horses ( locked on horse's face ) achieving focus is pretty good with the 70-200 L F2.8 IS USM II, BUT I don't generally use single point Spot mode ( I would normally use single point AF or AF Point Expansion, Surround ) - could that be the issue?

Because of the motion of a horse Cantering sometimes the odd one fails and may lock on a high contrast point on the bridle instead of the eye now and then ( but maybe my error ).
But that dog looks as though it might be going quite a bit faster than a Dressage horse ( very controlled Canter speed ) - so is 1/800 fast enough ( that is a question not a recommendation ).

OP has also locked on originally with one of the hypersensitive focus points of the Lens - so in my mind has given it every chance.
IMO for those without that lens - its very quick to AF in light like that, almost instananeous.
Obviously that is relevant - so my reference is the 70-300 L , which is quite fast especially in that light - And that lens would have nailed it. The 70-200 II is noticably quicker, and follows well.

( note my observations are with a 5D3 - that required no MFA adjustment at either the 70 or 200 end. )

Submariner wrote in post #17353859
... I don't generally use single point Spot mode ( I would normally use single point AF or AF Point Expansion, Surround ) - could that be the issue?

Worth checking out. I wouldn't use spot unless I'm after a small stationary subject in a jumble of other objects.

You're right, I didn't check the details enough to see that spot AF was used. Consider spot AF a special tool for things that are behind obstacles, like animals behind a fence, perched birds behind branches and such stuff. Use a normal AF point. Use a point with assist points if you have problems keeping a single AF point on the target all the time.

If you use one of the high accuracy (not high sensitivity) points, so much better, but when doing AF on moving subjects, the advantage is less prominent.

apersson850 wrote in post #17354183
You're right, I didn't check the details enough to see that spot AF was used. Consider spot AF a special tool for things that are behind obstacles, like animals behind a fence, perched birds behind branches and such stuff. Use a normal AF point. Use a point with assist points if you have problems keeping a single AF point on the target all the time.

If you use one of the high accuracy (not high sensitivity) points, so much better, but when doing AF on moving subjects, the advantage is less prominent.

Sorry I should have said "'dual cross type' - higher precision focusing points (with F2.8 or greater lenses) - I was being lazy i.e the 5 down the middle with that lens.

Likewise when I said I 'never' use Spot - think I have had to use Spot through a railed fence once or twice. To get at the subject where otherwise it will leap to focus on the fence.

I have used AI Servo a couple of times before on a 6D. But, I would say I am a beginner at it. I use Back button focus and hold it to get focus for a second or two before I press the shutter. It was also in high speed shooting mode.

I thought the same thing at the time, So I tried it with the shutter at 1/1250th as well. The dog wasn't running that fast as the picture makes her out to be.

Absolutely. The lens is great with stills. Spot on.

I'm not sure why I couldn't multi-quote. Oh well.

I'm going to try it out with a faster shutter speed (1/2000th) and more focal points and see what happens. Does everyone think Situation 4 would be the correct AF system to use, or should I use a different one?

Thanks for everyone's help.

hang your cross wrote in post #17355809
I'm not sure why I couldn't multi-quote. Oh well.

I'm going to try it out with a faster shutter speed (1/2000th) and more focal points and see what happens. Does everyone think Situation 4 would be the correct AF system to use, or should I use a different one?

Thanks for everyone's help.

The 1/1250 SS is plenty fast. It would help way more to close the shutter down more than f 3.5. At 200mm the depth of field is pretty thin at only 8 meters. Your ISO is still low so raise it to allow for a faster SS instead of using a low f stop.

Nogo wrote in post #17356050
The 1/1250 SS is plenty fast. It would help way more to close the shutter down more than f 3.5. At 200mm the depth of field is pretty thin at only 8 meters. Your ISO is still low so raise it to allow for a faster SS instead of using a low f stop.

I too would have thought 1/1250 would have been OK.
Something wierd here, as it says focus achieved, yet it looks as though the grass in front of the dogs paws (where the paws are circa in the same FP as his eyes ) is lightly shaper than his eyes.

Having that lens myself, even if the F No was 3.5 - so admittedly delivering a pretty thin DOF AT 200mm - OK max sharp focus might have missed his eye, but that lens lens is so quick to focus - in good light, surely somewhere on the dogs fur would be sharp , no?

I am assuming when you said you tried it at 1/1250 - was that also OOF?

If so , just a crazy thought, as it looks like movement blur - and because the dog is lower than your eye; were you swinging the lens down fast, as he approached, and thus creating motion blur?

Wouldn't the whole picture be out of focus then? That could very well be the case though. If it's nice out tomorrow I'll try this again.