Hood Mount; Distance Scale - Canon EF 200-400mm f/4L IS USM Extender 1.4X Instruction

11. Infinity Compensation
Mark
Distance index
To compensate for shifting of the infinity focus
point that results from changes in temperature.
The infinity position at normal temperature is the
point at which the vertical line of the distance
scale L mark is aligned with the distance index.
For accurate focusing in MF on subjects at infinity
distance, look through the viewfinder or at the
camera's LCD display while rotating the focusing
ring.
Infinity compensation mark
12. Hood
Lock knob
The special hoods that come with all these
lenses cut out unwanted light and protect the
front of the lens from rain, snow, and dust.
To attach the hood, loosen the hood lock knob
by turning it counterclockwise. Fit the hood onto
the lens's hood mount, and tighten the lock knob
to fix it in place. Use the same procedure, in
reverse, to remove the hood.
ENG-18