Canon EF 17-40mm f4L USM - Manual (Page 5)

ENG-4
See your camera’s instructions for details on
mounting and detaching the lens.
1. Mounting and Detaching the Lens
The lens mount has a rubber ring for enhanced
water- and dust-resistance. The rubber ring may
cause slight abrasions around the camera's lens
mount, but this will not cause any problems. If the
rubber ring becomes worn, it is replaceable by a
Canon Service Center at cost.
• After detaching the lens, place the lens with the
rear end up to prevent the lens surface and
electrical contacts from getting scratched.
• If the contacts get soiled, scratched, or have
fingerprints on them, corrosion or faulty
connections can result. The camera and lens
may not operate properly.
• If the contacts get soiled or have fingerprints on
them, clean them with a soft cloth.
• If you remove the lens, cover it with the dust
cap. To attach it properly, align the lens mount
index and the
K index of the dust cap as shown
in the diagram, and turn clockwise. To remove it,
reverse the order.
COP
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