AI Servo AF not reliable in 5D4

drolo61

EOS 80D
Aug 31, 2012
109
0
Hamburg - Germany
Dear all,

I have had an intense weekend shooting children's hats for my wifes company.

I use BBF with AI servo to be able to follow the running little beauties. For the first time I have a relatively lower rate of critically sharp images (70-200 2.8 II IS), although working faster than 1/200 and ~ at least 4.0

The "non-keepers" happen also with more or less static subjects and I have no real idea why.

Nevertheless I noticed, that very subtle movements seem not to be detected/followed by the AI Servo. Has anyone encountered a similar behaviour? Will try to go back to <One Shot> to see, if this brings up my rate of keepers in these situations.

Sending the body to CPS is no option, as we have to finalise the shooting befor May 25th.

Second option of cause can be rent, but so far we do get the keepers needed and budget is scarce.

Thanks for any help - as always highly apprechiated

Cheers
Olaf
 

Valvebounce

EOS 5D SR
Apr 3, 2013
4,201
166
52
Isle of Wight
Hi Olaf.
Just a thought, might you have accidentally selected AI Focus, this lets the camera decide whether things are static or moving, there must be a reason Canon left it off the 1D series bodies! :)

Cheers, Graham.
 

drolo61

EOS 80D
Aug 31, 2012
109
0
Hamburg - Germany
Hi Graham,

I will check that - I intend to work with AI Servo, as I need to catch playing kids.

My isse is, that very small movements are not (always) detected (properly).
Or I have more difficulties steadying my lens than I would like to have, I dont know.

Thanks
Olaf
 
May 2, 2018
1
0
Visit site
Hi,
try these settings:
  • AI Servo Tracking Sensitivity +2
  • AI Servo 1st image priority "Focus"
  • AI Servo 2nd image priority +1 or +2

Best, Daniele
 

Handrews

EOS M50
Mar 10, 2016
35
0
Hi there,

It might also be useful if you could provide some info about the lighting conditions and distance from subjects.
If lighting is dim, AI servo tends to be less reliable than One shot.
What about the number of AF points? If set to one point, try to increase the number of AF points and see if it makes a difference.
The distance to subjects should also be taken into account, if the kids are running towards you, 1/200 is not enough.

Hope these help!
 

BillB

EOS 6D MK II
May 11, 2017
1,112
356
drolo61 said:
Dear all,

I have had an intense weekend shooting children's hats for my wifes company.

I use BBF with AI servo to be able to follow the running little beauties. For the first time I have a relatively lower rate of critically sharp images (70-200 2.8 II IS), although working faster than 1/200 and ~ at least 4.0

The "non-keepers" happen also with more or less static subjects and I have no real idea why.

Nevertheless I noticed, that very subtle movements seem not to be detected/followed by the AI Servo. Has anyone encountered a similar behaviour? Will try to go back to <One Shot> to see, if this brings up my rate of keepers in these situations.

Sending the body to CPS is no option, as we have to finalise the shooting befor May 25th.

Second option of cause can be rent, but so far we do get the keepers needed and budget is scarce.

Thanks for any help - as always highly apprechiated

Cheers
Olaf
If very subtle motions are an issue, maybe shutter speed is the problem, especially if you are pretty close to the subject. Can you tell if the problem photos are related to slower shutter speed? Anyway, it might be good to try faster shutter speeds.

Also, the 5DIV manual around pages 127-130 describes possible AI servo settings. Also, It might be useful to experiment with manually selecting a single point with expansion to the surrounding points.
 

drolo61

EOS 80D
Aug 31, 2012
109
0
Hamburg - Germany
dear all,

thanks for the valuable input.
I will check all recommended details tonight.
The next shooting will be tomorrw afternoon and I will let you know of the outcome.

@daniele - will use your settings and have already re-read the manual in the sections @BillB pointed to

Lightning conditions where mid-ok I would say. Overcast skies during normal daylight. Lightning was ok at ISO 800, 1/320 and F5.6. I used a softbox to light the faces under the hats. I use <one AF spot> point, as I need to get "under the brim". Sometimes I can understand what went wrong - I used the "show focus point" LR plug-in.

If I hit the brim of a cap because the head (or I) moved slightly, than out-of-focus is expected behaviour.

@handrews - it is for this accuracy needed, that I did not (yet) expand the numer of points. In the manual the described behaviour of such settings is that focus will be locked on the nearst part of the subject - in most cases brim or nose but the intended eye.

But sometimes - even with the focus point right on target - I get miss focussed shots.

I will show examples, should the problem still be present after the tweeaks have been applied and the shooting.
is done.

Enjoy your day, people, and thanks again for the fast responses.
 

Don Haines

Beware of cats with laser eyes!
Jun 4, 2012
8,094
1,574
Canada
I have no specific experience with the 5D4, but in other cameras I have noticed that while AI Servo works well on moving subjects, it seems to fail on stationary or slow moving ones.... I tend to use the custom functions for the camera, and set up C2 with Ai Servo for moving objects and to set up 1 shot in C1 for stationary objects.
 

Mikehit

EOS 5D MK IV
Jul 28, 2015
3,210
395
Don Haines said:
I have no specific experience with the 5D4, but in other cameras I have noticed that while AI Servo works well on moving subjects, it seems to fail on stationary or slow moving ones.... I tend to use the custom functions for the camera, and set up C2 with Ai Servo for moving objects and to set up 1 shot in C1 for stationary objects.
Using AI Focus on stationary subjects is a recognised issue when trying for a very shallow DOF because the algorithm is hunting for movement that is not there and the shallow DOF shows this up.
As has been mentioned above, Canon will tell you that the best AF is achieved using stationary subject, centre point, one shot focus on good contrast subject - anything from there will not be as good, but in a vast majority of conditions will be good enough.
Also remember that the AF area in the focussing mechanism is nearly always slightly larger than what you see in the viewfinder so if you are focusing on the (relatively) low contrast in the shadow of a hat you may see some variability.
 
Mar 14, 2012
2,286
174
I've used the 5D4 + 70-200 IS II for soccer and portraits with no problem (AI servo and one shot).

Have you tried checking AFMA? If you have a tripod, mount the camera and try focusing in one shot on a high contrast static subject using the center point with spot. Then switch over to live view and focus on the same subject. The "sharpness" on the magnified live view should not change much. If it is, then the body/lens combo needs to be AFMAed. I'm assuming the body is rental or a new purchase and that the 70-200 works well with your other cameras. If it works well for one shot without AFMA then I'd suggest playing with the use cases for AI servo or trying for a higher contrast target at the same distance.
 

YuengLinger

EOR R
Dec 20, 2012
2,434
488
Southeastern USA
Have you spent time testing the camera and lens in good light under controlled condtions? That is, with a subject first walking towards you, then running towards you, then moving a little more erratically?

Or are you basing your assessment only on the results of a recent "live" photo session?

You need to eliminate as many variables as possible, then try making some changes to your AF scenario settings. And also try with more than one lens to determine if the lens or the body is a source of problems.

Keeping up with kids in the viewfinder isn't always easy...I have been having better luck with the four-point spread when they are running around. With a 70-200mm, once I get beyond 85mm, just a tiny motion of the lens results in a big change to where the AF spot hits, and with little kids moving erratically, I sometimes move too far off the target and get the background.

And don't forget to blow clean the AF sensor area! That solved some similar issues I was having a few months back.

But you can't know if it is technique or a hardware problem until you have patiently gone through a controlled practice session with different scenarios.

As far as sending to CPS, they usually have equipment back to me within 10 days of me sending it to them, which is still close but should give you enough time if you get it out this afternoon or tomorrow.

Do you have a backup camera that might be good enough?

Sounds like a frustrating time to discover an issue, but you might be able to solve it with testing and changing settings.

Check out this link to go through a checklist and maybe get some more ideas...

https://lensvid.com/technique/a-guide-to-solving-autofocus-problems/
 

LDS

EOR R
Sep 14, 2012
1,551
132
This is for the 5DIII but should still be useful:

https://www.learn.usa.canon.com/app/pdfs/quickguides/CDLC_EOS-1DX_Mark_III_AF_tracking_QuickGuide.pdf

Especially, selecting the proper "case" (or selecting proper parameters directly) for the subject is important, because it changes how the AF reacts to change in speed and direction. Especially "Acceleration/Deceleration Sensitivity" could impact how the AF behaves when subject in movement stop.
 

drolo61

EOS 80D
Aug 31, 2012
109
0
Hamburg - Germany
@YuengLinger - camera with lens has been ALMAed via Focal - the set performed well - testing has been done ~6 month ago - will re-test over the weekend, if issue continues - current assessment is based on live shoot - will blow clean and stick to <One shot> for really critical pictures - unfortunately currently no back-up, but get one - there is enough keepers to survive this job ;-)

@randomorbits - AFMA about 6month old and (at the time) spot on - will re-do

@mikehit - will go switch more frequently between <one shot> and <AI servo> depending on the complexity of the situation - will be an additional challenge on top of keeping track of the subject(s) - I do this for ~15 years now and the ambition of my art director (alias wife) always raises with the quality we produced last time ;-) - Thanks for mentioning the larger area covered - that may be the clue I have been looking for - will try to get some safety margin away from the brims...

@DonHaines - I recall, insoired by your idea for C1 and C2, that there has been a You Tube tutorial that showed how to configure one of the buttons to switch specifically between these two modes <One shot> and <AF servo> - will share if I find it

@all - thanks people ;.-)
 

Mt Spokane Photography

I post too Much on Here!!
Mar 25, 2011
15,421
674
Focus issues that suddenly pop up can often be traced to dust on the AF sensor that sits behind the mirror at the bottom of the camera. You can use a rocket blower to try and dislodge any dust or debris, be gentle.

Google how to clean it if necessary.

Thats about the only thing that can be serviced by the user.
 

sebasan

EOS T7i
Mar 12, 2016
95
46
sebasantos.1x.com
Hi, my two cents, there are also some buttons that you can configure to change AI Servo to One Shot or viceversa. In situations when the subject is almost static, you can change your configuration of AF without changing from C1 to C2 or similar.
 

unfocused

EOS 5D SR
Jul 20, 2010
4,887
1,171
65
Springfield, IL
www.mgordoncommunications.com
Personally, I think people are making this too complicated.

I doubt if one-shot vs. servo is your problem.

First, how many autofocus points are you using? One point, expanded, zone, all? With moving subjects, one of the expanded points is usually best.

Second, what autofocus case are you using? If it's just one child then you should set it to track on the subject. The default case is pretty good, but it doesn't hurt to try others.

Finally, be realistic about both depth of field and shutter speed. Getting a running child's eye in focus at f2.8 is no small feat. Nor is stopping the action if they are hyperactive.

Finally, the high pass filter is your friend. Learn to use it. Short tutorial: After your adjustments are all done in Photoshop, copy everything and merge the copied layers into a single layer (always copy, so you preserve the original layers in case you need to go back.)

Duplicate the layer. Go to blending modes, choose "hard light." Go to filters, pick High Pass. Choose a fairly small amount like 2-3 px. Compare the image with the high pass layer on and off. If you've done it right, you will be amazed at how much sharper the eyes look.

Now, add a black mask to the high pass layer, so everything is obscured. Then paint the mask white for the eyes, mouth, hair and other details you want sharp.

High pass will increase the perceived noise, but if you are shooting at ISO 400 or so, it won't be noticeable in the final product. I've saved hundreds of images this way.
 

foo

EOS T7i
Sep 10, 2016
78
0
drolo61 said:
@DonHaines - I recall, insoired by your idea for C1 and C2, that there has been a You Tube tutorial that showed how to configure one of the buttons to switch specifically between these two modes <One shot> and <AF servo> - will share if I find it
The manual tells you how, but relatively easy to do in the button config menu. You can only do it with certain buttons though.

Two ways to set the button up, either it toggles the mode every time you press it, or hold it down for AI servo when you're in one-shot, release and you go back. Possibly other variations, but that's the way I use it.

If I recall, you can do much more than just flip the mode, you can also configure some (all?) of the settings when you hit the button which allows you to have different subsets of AI Servo on a couple of different buttons. So quite versatile assuming you can remember what you programmed each button to do - I can't really so tend to stick with just the one.
 

Don Haines

Beware of cats with laser eyes!
Jun 4, 2012
8,094
1,574
Canada
foo said:
drolo61 said:
@DonHaines - I recall, insoired by your idea for C1 and C2, that there has been a You Tube tutorial that showed how to configure one of the buttons to switch specifically between these two modes <One shot> and <AF servo> - will share if I find it
The manual tells you how, but relatively easy to do in the button config menu. You can only do it with certain buttons though.

Two ways to set the button up, either it toggles the mode every time you press it, or hold it down for AI servo when you're in one-shot, release and you go back. Possibly other variations, but that's the way I use it.

If I recall, you can do much more than just flip the mode, you can also configure some (all?) of the settings when you hit the button which allows you to have different subsets of AI Servo on a couple of different buttons. So quite versatile assuming you can remember what you programmed each button to do - I can't really so tend to stick with just the one.
For me, it was easier to remember.... C1 is still, C2 is moving.... and for the still targets I am on one AF point, for the moving it is the central zone (7D2) or all the points (6D2). This way I am a bit more consistent across cameras...