Canon EF400mm f/4 DO IS II USM Instructions Manual page 20

15. Drop-In Filters
A 52(WII)-series drop-in gelatin filter holder with
a glass filter is included with the lens. The drop-
in filter holder can be used fitted with a gelatin
filter (sold separately).
<Installing and Removing>
To remove the drop-in filter, press in the left
and right lock buttons and pull the filter holder
straight up out of the slot.
To install the drop-in filter, push the filter holder
straight down into the slot until it clicks into place.
O O
The filter holder can be installed facing either
forwards or backwards.
Because the lens optics are designed to include a
glass filter, you must always install the filter holder,
even if no gelatin filter is fitted.
<Using a Gelatin Filter>
Lift up the holder's retaining plate.
Cut the gelatin filter as shown and mount it in
the holder.
Return the retaining plate to its closed
position.
The Drop-In Screw-Type Filter Holder 52(WII) and
Drop-In Circular Polarizing Filter PL-C52(WII) are
also available (sold separately).
14mm
14mm
47mm
47mm
ENG-19