Canon RF 100-400mm F5.6-8 IS USM Instructions Manual page 16

9. Filters (Sold separately)
You can attach filters to the filter mounting thread
on the front of the lens.
Only one filter may be attached.
z
If you need a polarizing filter, use the Canon
z
Circular Polarizing Filter PL-C B.
Detach the hood when adjusting the polarizing
z
filter.
ENG-15