Issue with R8 BBF

[mdwecht]

I am sports photographer and recently attempted to use an R8 with RF 70-200mm f2.8 in place of my 1DX Mark III with EF 70-200mm f2.8 configuration. I configured the R8 to use a single point BBF configuration in manual with auto ISO set to 1/800 and f2.8. Every so often when I push BBF the camera would not focus. The lens is set to AF with Stab. = OFF and Full Focus. When the camera did not focus the EVF was milky white and I had to aim the camera at the ground hit BBF several times and then if it started focusing hold BBF down as I brought the camera up to the action. Due to this issue I missed several important shots. Has anyone experienced this type of issue? If so any suggestions?

[Waddizzle]

What are you trying to photograph?  Night or Day?

If you have any UV, ND, or CPL filter on the lens, then I strongly suggest that you remove it.  If you feel the need for some type of “protective filter” on the lens, then I recommend a high quality, clear filter.  I use B+W Nano Clear filters, exclusively.

[mdwecht]

Thanks for your response. I am currently photographing cross country, day light, and soccer, day light transitioning to stadium lights. I had the focus issues both in day light and stadium lights. I do have high quality UV filters on all of my lenses and have had no issues for years. Are you thinking that the R8 and or RF lens has issues with focus with filters? I will try some shots without the filter to see if it makes a difference.

[Tronhard]

FWIW, I have no issues with filters on all my lenses: both EF and RF, shooting in good or dim light - I generally use high-quality UV0 filters.

[Tronhard]

I shoot with single point  BBF, but for action I have servo focus turned on.  That way I just hold down the BBF button to have continuous refocus, but if the subject is not moving closer or further away, I jut prod the BBF button.  See:

[mdwecht · Accepted solution]

I experimented with the EOS R8 AF settings and found that the fix for my issue was setting:  Lens drive when AF impossible = ON. I am still not happy with the focus speed when acquiring a new subject.