R5 and RF 100-500 eye autofocus issues

[ekviera]

Hello. I have recently encountered issues with the RF 100-500 eye auto focus. The last two outings, I have tried to use the eye auto focus and the 100-500 lens does not lock on the eye. I can then switch to the RF 800 f/11 and the eye auto focus works without issue. The first time it happened I checked to see if I needed to update the firmware on the lens/camera. There was a firmware update for the R5 so I applied it and hoped that would work. I went out again this past weekend and had the same issues with eye autofocus not working. Any suggestions on what could be happening?

Thanks,

Eric

[p4pictures]

Firstly for the EOS R5 eye autofocus only works when the camera AF method is set to face + tracking, or you have a back button configured to eye detection AF and use that. 

With the RF 800mm F11 lens you only see a central frame where AF is working. For the RF 100-500mm the whole frame is used to detect the subject. 

EOS R5 and EOS R6 (original "mark I" versions)

• Eye detection only works with face + tracking AF
• Subject detection works with face + tracking or any of the three Zone AF areas
• There is no subject tracking or face / eye detection with spot AF, 1-pt AF, AF with expansion

[ekviera]

Since the eye autofocus worked on the RF 800 f/11 immediately after taking of the 100-500, wouldn't that indicate the camera is set up correctly? Thanks for the reply.

[Tronhard]

I will  hazard that what my respected colleague Brian is getting at is that the 800mm prime is limited to what area of the Field of View it can focus on and is essentially concentrating on the centre of the image, thus avoiding a lot of clutter - assuming you are placing the subject there.

The RF 100-500 can, by default, look for faces or objects that look like faces anywhere across the image and it can be fooled by that.   Likely the fast, jerky movements of the bird, plus the wing beats are a distraction.  I start with centre point spot, and then let eye tracking take over once I have got it locked in - that way I can precisely tell it where to start looking - in much the same way as the 800mm does for you.

[ekviera]

Thanks. This was with birds sitting still (Bald eagles perched on tree branches) and ducks sitting mostly still on the pond. The last time was at the zoo and the rf 100-500 wouldn't autofocus on the eye of an elephant. I might just need to call Canon support and talk through the issue. I am likely not articulating it properly here.