Canon EF 135mm f2L USM - Manual (Page 6)

ENG-5
4. Infinity Compensation Mark
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 L mark is
aligned with the distance indicator on the
distance scale.
For accurate manual focusing on subjects at
infinity distance, look through the viewfinder while
rotating the focusing ring.
Infinity compensation mark
Distance index
3. Switching the Focusing Distance Range
You can choose the focusing distance range with
a switch. By setting a suitable focusing distance
range, actual autofocusing time can be shorter.
¡EF135mm f/2L USM :
q 0.9 m / 3.0 ft. – ∞ w 1.6 m / 5.2 ft. – ∞
¡EF200mm f/2.8L II USM :
q 1.5 m / 4.9 ft. – ∞ w 3.5 m / 11.5 ft. – ∞
¡EF300mm f/4L USM :
q 2.5 m / 8.2 ft. – ∞ w 6 m / 19.7 ft. – ∞
¡EF400mm f/5.6L USM :
q 3.5 m / 11.5 ft. – ∞ w 8.5 m / 27.9 ft. – ∞
If you autofocus outside the set focusing distance
range, the lens may stop focusing at the start of
the focusing range; however, this is not a
malfunction. Press the shutter release button
halfway again.