Setting The Aperture; Infinity Compensation Mark; Infrared Mark - Canon EF135mm F2L USM Instruction

6. Setting the Aperture

The lens aperture is set with the
camera.
7. Infinity Compensation
Mark
The distance scale can be
turned in excess to correct the
point of infinity focus which
shifts depending on the
temperature.
At 20˚C, the point of infinity
focus is achieved when the
distance scale is aligned with
the top of the letter "L."
To ensure accurate focus, look
through the viewfinder and
check the focus.

8. Infrared Mark

(EF 200 mm f2.8L II USM
EF 300 mm f4L USM
EF 400 mm f5.6L USM)
The infrared mark is used when
black-and-white infrared film is
used. After achieving focus,
shift the current distance setting
at the distance index to the
infrared mark to compensate for
the focusing difference. Also
use an infrared filter on the
lens.
ENG-6