EOS R5 Mark II AF jumps to wrong subject after few seconds

[pedz]

The past two days I've been using the Canon RF 100mm f/2.8 L Macro but I've seen it with other lenses such as the 100-500mm.  I've also seen it mentioned in YouTube videos by the likes of Ian Wegener and Duade Paton.  They are typically using the RF 600mm f/4.

Focus on a complex subject such as a honey been in a flower with the various parts of the flower around the bee.  Or a bird with branches, leaves, and weeds near by.  Even if the subject isn't moving and in the clear, if the focus button is held down continuously the camera will get bored or something after about five to ten seconds and just start jumping the focus point around usually on something closer.

Today I was using mostly the flexible zone AF 1.  For a while I had the subject of animals but changed it to none.  I tried both many various settings but nothing really seems to solve the issue. 

I've used Canon cameras going back to the 1D and I've never noticed this particular behavior.  I will say that I am not sure I ever just held the focus button down for a long time.  By the "focus" button, I mean either the shutter button when it is set to the default setting or the AF button.  As far as I know, eye tracking is off (but I should check that to be sure).

I mostly wanted to start a discussion about this.  I'm not sure if it is a real issue or what.

My wild suggestion is another button for feed back to the focusing algorithm.  When the focus point is on the place the photographer wants it, he could push this other button and says "YES!!!!  Keep the focus right there".

I can kinda forgive the algorithm when I'm trying to focus on a bee since it isn't really a bird.  But this happens all the time with birds even after it detects the eyes.  To me, it just seems like something is wrong.

[chrishoesel]

I believe you can control the behavior by altering some of the parameters of the focus scenario you're on.  For example, you can use the slider control in the AF menu to control how prone the AF is to being locked-on to a subject, vs its variability.  You can manually select certain behaviors.  I don't shoot sports or birds, so I can't tell you the exact menu locations, but it is in the AF menu under scene selection options I believe.  (at work so no camera on hand to check)

Also remember that the Eye AF control helps in this situation to lock the focus on a particular subject in conjunction with the AI autofocus modes.  (I use the Eye-AF to tell the system to stay locked on to a particular person when multiple people are in frame)  For example, Eye-Detect AF + Eye AF control to jump from auto-selected subject to another.  You can also use the joystick to flick back and forth between auto-selected subjects.

I'm sure you tried some of these other techniques but your idea of a feedback loop button so the "AI" learns would be a powerful addition and an amazing idea I've never seen before.

[Hazel_T]

Hi pedz,

I'm sorry to hear your EOS R5 Mark II is having difficulty staying on your select subject. The suggestions chrishoesel made can help in cases like this. There are a couple of other settings to double check too.

The first is when you are photographing a bird or a bee make sure Subject to Detect is set to animal. It is geared more towards things like cats, dogs, and birds, but it can help with bees too.

The other thing is related to chrishoesel's response. The EOS R5 Mark II doesn't have servo focus cases, but you can customize the servo behavior like he is describing. To do that go into the menu on the camera, go to the third page under the AF tab, and you will be on the Servo AF Character menu. To customize it set it to M and the setting you will want to try adjusting is the tracking sensitivity. To make the camera prioritize sticking to your selected subject set tracking sensitivity to -1 or -2. The further to the negative it is set the more the camera prioritizes staying on the same subject. That should help keep it from constantly searching for new subjects to focus on.

[pedz]

Thank you for your reply.  I've piddled with the various settings but it might help to see what I'm talking about specifically.  This link will take you to a particular spot 6:04 in a YT video.  This is the new firmware.  You can back up and watch the whole video where he gives a lot of details of firmware, settings, and techniques if you want.

He graciously says that this is true for all mirrorless bodies that he's used and also graciously acknowledges how great the AF is in general -- which I 100% agree with.  But this particular nit is very frustrating.

On a slightly different topic: I believe it is true that when AF servo, there is no way to engage the manual focus.  Is that correct?  (i.e. I would have to flip the AF/MF switch off, adjust, then flip it back on or some similar act).  Perhaps create a setting where if the AF button is released but before the camera goes idle, manual focus would be enabled.  Then when the camera sticks somewhere the user can release the AF button, move the focus ring, and re-apply AF to get the camera off of the stuck position.