RF400mm F2.8 L IS USM makes sound as it focuses

[1Cowboy4u]

Purchased the RF400mm F2.8 L IS USM and mated it to my R5 for about 2 weeks now.  I set the camera to manual with the lens set to auto focus.  At first while carrying the camera in the field, I did not note an audible sound as the camera continually tries to focus.  Now the sound is quite noticeable.  I would not think this normal for this lens.  Thoughts would be appreciated.

[Tronhard]

Hi and welcome to the forum:

In the focus menu (ref P411 of the Advanced User Guide), there is a setting for Continuous focus, which causes the camera to attempt to autofocus all the time (logically enough) and that will waste a lot of battery power  - if you find it is on, turn that off it and it should resolve that issue.

That section is something you pay special attention to as it cuts to the heart of many features of the camera.  Given you are using a super telephoto, that is critical for gaining and keeping focus for moving subjects.

[1Cowboy4u]

Thanks for the pointer... as stated, continuous auto was enabled.  If I wasn't so taken with this lens performance - possible would have thought of this. Regards