EOS R5 Animal Eye AF focusing on wrong horse at races

[sdeckerphoto]

Hello,

I have been using an EOS R5 and an RF100-500mm f/4.5-7.1 L IS USM for several years now to shoot horse racing.  I use animal eye af.  The past several months, when I shoot on turns, when the field of horses comes around the turn and I am shooting head on, the camera at first focuses on a horse behind the horses at the front of the pack until they get closer.  I am not doing anything differently than I have done for years and I have not recently updated my firmware.  I am having to stop down much further than I would like to try to mitigate the issue.  Has anyone experienced something like this?

[wq9nsc]

I agree with Steve that a restricted group of points is what you need for selecting/controlling which horse you want in focus.  I shoot a lot of sports and typically use center point with four point expansion to ensure that the camera is focusing on what I want it to.  This also helps keep you "focused" on the proper part of the action.  With fast moving sports like soccer and basketball, the desired subject changes rapidly and for any situation where you are picking a specific "target" out of the action then you and the camera have to operate together as a system.  I find that for most situations allowing slight expansion around the single point is the best choice with fast action because this still allows tight control over what drives the AF system but still allows it to work well if the target slips off the single point but is still within the selected expansion.

As Steve pointed out, the camera AF system is going to be biased towards the center of the array and to the closest object within those parameters.  With my photography scenarios, that doesn't work well for me and I think you experience the same with horse racing.  Of course also spend some time understanding the way the different selected cases bias the AF performance to choose the one most suitable for you.  I would think that the AF behavior when another object briefly crosses in front of your intended focus point would be critical and the AF cases and fine tuning within modify whether the focus is "sticky" briefly staying with the prior object or whether it instantly locks on the new object.

I am one of the few people who don't use BBF and this is because I shoot events with at least two and sometimes three camera bodies and lenses.  Often I will switch quickly between one body with a 400 f2.8 to the other with a 70-200 f2.8 as a play develops towards me.  NOT having to immediately lay fingers on both the focus and release buttons is a critical time saver in this instance and instead I have the AF on button programmed as an AF stop button if I need to lock focus on something.  I use the stop AF button array at the far end of my 400 f2.8 with that lens and other "great white" lenses that have the stop array but the camera button is useful to me for small lenses like the EF 70-200 f2.8 that don't have stop buttons.  With a single body, the BBF would be fine but when switching between bodies during a play the few extra milliseconds of using two buttons would mean missed captures.  The attached is from Friday night when I started with the 1DX III/EF 400 combo on what I expected would be a running play well downfield from me but it quickly turned into a pass play with this interception that I caught by grabbing the other 1DX III body and EF 70-200 f2.8 lens that I use with a dual camera harness. I barely got the proper camera aimed at the action in time and even a brief additional delay to touch a separate focus button would have caused me to miss it so there is life without BBF 🙂

Rodger

1DX III/EF 70-200 f2.8 1/1,000 ISO auto (camera selected 1,000)

[Waddizzle]

“ I do use AI servo and back button focus, but how do I switch horses as they come by? “

You want to avoid AI Servo. Use Servo AF.

IMG_6118.jpeg

 

I suspect that this is 100% your problem. If you are using Subject Detection and/or Eye Tracking, disable them.  

I would use 1pt AF or one of the Expand AF modes. I would enable WAT, Whole Area Tracking. If not, then will revert to basic instincts and track the nearest target to the camera.

IMG_6119.jpeg

 

You might want to try changing BBF. 
 Restore AF-ON to the Shutter button. Change the [AF-ON] button to AF-OFF. If I lose tracking on a subject, one tap resets the AF. For me, this works better than releasing BBF and pressing it again. 

So, where’s the Initial AF Tracking Point located? I have a gut feeling that the camera uses the AF point chosen for 1pt AF.  When I reset the AF by tapping AF-OFF, the activAF point switches to the center, and tracking resumes when I release AF-OFF.  Of course, I am maintaining my half or full press on the shutter.
 

[sdeckerphoto]

I misspoke.  I use Servo AF, not AI Servo.  I have never used Expand AF Area.  Forgive me for being a little dense here, but it will track a subject once it focuses on something?

[stevet1]

sdecker,

No. To the best of my knowledge, single point or an Expanded Area don't do any tracking, but in Servo Mode,  it will keep focusing as long as you hold down that AF-ON button, or whatever button you have assigned to do your focusing. It will focus on whatever you point your camera at.

If you let go of the button, the camera will be focused, but it stops searching.

Steve Thomas

[Waddizzle]

“ I misspoke.  I use Servo AF, not AI Servo.  I have never used Expand AF Area.  Forgive me for being a little dense here, but it will track a subject once it focuses on something? “

The camera does not track subjects when WAT is disabled. Notice what having it disabled means. It means subject detection and eye tracking are also disabled!  Leave those settings disabled.  Might not work on horses. 

When WAT is disabled, then the photographer is fully responsible for tracking subjects.  It takes practice to become good at it. 

The others have suggested to only use a single AF point. I am going to recommend one of the single AF point modes with the surrounding assist points. These modes are less demanding on the skill required to keep the AF point on moving subjects. But, if you enable WAT, the camera should do a decent job of tracking a single horse. It might help to set up the AF-OFF button for AF resets. 

[Waddizzle]

“ No. To the best of my knowledge, single point or an Expanded Area don't do any tracking, but in Servo Mode,  it will keep focusing as long as you hold down that AF-ON button, or whatever button you have assigned to do your focusing. “

Yes, they will track when WAT is enabled.  Pretty display, too.

[Waddizzle]

“ For now, I would advise you to disable Subject Detection and Eye Tracking.  I am getting the impression that you are too far away for those features to be effective.  Take advantage of the camera AF System instinct to lock focus on the closest object within the field of view. “

IMG_6122.jpeg

 

 That is from the first link you posted. Is this a good or bad example. You are probably too far away for eye tracking to be effective. Besides, the horses eyes are mostly covered. I guess that probably protects against flying dirt and debt.

Judging from the apparent distance, and the aperture of your lens, all the lead horses should be in focus. But they may not look very sharp if zoom in on the heads. 

Have you checked to see where your locked SF point is located?

[sdeckerphoto]

This is a good example.  It was shot wide open at 7.1, and if you zoom in all the way, the front horse's head is in focus the most.

[Waddizzle]

“ This is a good example.  It was shot wide open at 7.1, and if you zoom in all the way, the front horse's head is in focus the most. “

————————-

I would agree that this photo captured well. I assume that if the aperture was f7.1, then the focal length was 500mm. 

IMG_6124.jpeg

I am not sure what could go wrong with other photos, except that you missed focus for some reason.  You, not the gear. The depth of field at 100 feet away is around six feet.  Not e very horse in the pack will be focus, just the lead hirse(s).  

Have you checked to see where your locked AF point is located? You cannot claim the gear locked Dixon the wrong horse if you have not checked. 

[johnrmoyer]

I do not do horse races, but hope some of this might be helpful anyway.

I looked at the last image you listed using exiftool and compared settings you used to the ones I use when trying to focus on the eye of a bird.

One difference I noticed is that you used "[MakerNotes:Camera] InitialAFPointInServo : Auto" which I will use for a flying bird that might be anywhere in the frame and there are no other birds near. I find this helpful when the bird is difficult for me to track. If the bird were flying in a straight line, I would just pan using the initial AF point which I set to the center.

To pick out a single bird eye among several I use "[MakerNotes:Camera] InitialAFPointInServo : Initial AF Point Selected". When the camera can, it will track that initial eye and I can reframe after getting focus on the eye I want.

Otherwise, we use close to the same settings.

I do not use back button focus, but use half press of shutter button.