Canon RF 10-20mm F4 L IS STM User manual

ENG
Instructions

ENG-1
Thank you for purchasing a Canon product.
Canon RF10-20mm F4 L IS STM is a ultra-wide
zoom lens for use with EOS R series cameras.
z“IS” stands for Image Stabilizer.
z“STM” stands for Stepping Motor.
Conventions used in these instructions
Warning to prevent lens or camera malfunction
or damage.
Supplementary notes on using the lens and
taking pictures.
Camera Firmware and Camera
Applications
Please use the latest versions of firmware and
applications with the camera in use. For details on
whether the firmware and applications in use are the
latest version or not, and for details on updating them,
please check the Canon website.
If the camera’s* firmware is not a compatible
version, the following limitations will apply.
zMagnified view functionality is not available.
zIn some cases, the camera malfunction may
occur.
* Applies to the following camera models:
EOS R and EOS RP

ENG-2
Precautions to ensure that the camera is used
safely. Read these precautions thoroughly. Make
sure all details are observed in order to prevent
risks and injury to the user and other people.
Warning
Details pertaining to risks that may
result in death or serious injury.
zDo not look directly at the sun or other strong
light sources through a lens. This may result in
loss of sight.
zDo not leave a lens in the sun without the lens
cap attached. The lens may concentrate entering
sunlight and cause a malfunction or fire.
Caution
Details pertaining to risks that may
result in injury or damage to other
objects.
zDo not leave the product in places exposed to
extremely high or low temperatures. The product
may cause burns or injury when touched.
Safety Precautions

ENG-3
Handling Precautions
zDo not leave the product in excessive heat such as
in a car in direct sunlight. High temperatures can
cause the product to malfunction.
zIf the lens is taken from a cold environment into a
warm one, condensation may develop on the lens
surface and internal parts. To prevent condensation
in this case, first put the lens into an airtight
plastic bag before taking it from a cold to warm
environment. Then take out the lens after it has
warmed gradually. Do the same when taking the
lens from a warm environment into a cold one.
zIn order to optimize aperture control, there are
occasions in which the aperture blades will move
during zooming and focusing, even when the
aperture value is set for aperture-priority AE or
manual exposure, etc.
zPlease also read any lens related handling
precautions listed in your camera’s instruction
manual
.
Shooting Precautions
zT
his lens has a short focus distance, which means dirt
or dust on the surface of the front lens will show up
easily on photos. Use a commercially-available blower
to remove dirt or dust from the front lens surface.
General Precautions
zT
his lens has a wide shooting angle, meaning
sunlight or other strong light sources can enter
the image easily. This can lead to flares or ghosts
under some shooting conditions. To prevent this, we
recommend being aware of where the light source is,
such as photographing from shadows or other places
where a strong light source will not enter the lens.
Video Shooting Precautions
zThe lens is compatible with focus breathing
correction* when shooting video.
*
This refers to a function to correct for and reduce
changes in view angle that occur when focus changes.
zP
lease refer to the Canon website or the camera’s User
Manual to check if your camera allows focus breathing
correction, how to set it, and points to note about it.
zThis lens covers an ultra-wide angle, so in some
circumstances there may be image distortions or
slight movement around the sides of the frame
when focusing using focus breathing correction.
In that event, it might be reduced by the following:
• Change the focal length of the lens you are
using to telephoto.
• Reduce the focus speed. (Slow the AF speed for
Movie Servo AF.)
• Increase the f-stop. (It does not reduce the slight
movements around the edge of the frame.)

ENG-4
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions: (1) This
device may not cause harmful interference, and (2) this
device must accept any interference received, including
interference that may cause undesired operation.
Do not make any changes or modifications to the equipment
unless otherwise specified in the instructions. If such
changes or modifications should be made, you could be
required to stop operation of the equipment.
This equipment has been tested and found to comply with
the limits for a class B digital device, pursuant to part 15
of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference in a
residential installation. This equipment generates, uses and
can radiate radio frequency energy and, if not installed and
used in accordance with the instructions, may cause harmful
interference to radio communications.
However, there is no guarantee that interference will not
occur in a particular installation. If this equipment does
cause harmful interference to radio or television reception,
which can be determined by turning the equipment off and
on, the user is encouraged to try to correct the interference
by one or more of the following measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and
receiver.
• Connect the equipment into an outlet on a circuit different
from that to which the receiver is connected.
• Consult the dealer or an experienced radio/TV technician
for help.
CAN ICES-3 (B) / NMB-3 (B)

ENG-5
Focusing ring (→ 7)
Control ring (→ 8)
Image stabilizer switch (→ 10)
Lens function button (→ 9)
Zoom ring (→ 8)
Focus mode switch (→ 7)
Rubber ring (→ 6)
Contacts (→ 6)
Lens mount (→ 6)
Zoom position index (→ 8)
Lens mount index (→ 6)
Built-in lens hood (→ 12)
Gelatin filter holder (→ 13)
z For detailed information, reference page numbers are provided in parentheses (→ **).
Nomenclature

ENG-6
Lens mount index
Lens release button Dust cap
Attaching the Lens
Align the lens mount indexes of the lens and
camera, and turn the lens clockwise until you
hear a click.
Detaching the Lens
Turn the lens counterclockwise while pressing
the camera’s lens release button. Detach the
lens once it has stopped turning.
Please refer to the camera’s instructions for
details.
zSet the camera’s power switch to OFF when
attaching or detaching the lens.
zAttach the lens cap before detaching the lens
from the camera.
zAfter detaching the lens, place the lens with the
rear end up and attach the dust cap to prevent
the lens surface and contacts from getting
scratched. Make sure the lens and dust cap
mount indexes are aligned when attaching the
dust cap.
zContacts that are scratched, soiled, or have
fingerprints on them may result in faulty
connections or corrosion, which may lead to
malfunctions. If the contacts get soiled, clean
them with a soft cloth.
zThe lens mount has a rubber ring to improve
dust-resistance and water-resistance
performance. This rubber ring may cause
friction marks to appear around the camera’s
lens mount, although this will have no effect on
usage.
zRubber rings can be replaced at Canon Service
Center. (chargeable)
1. Attaching and Detaching the Lens

ENG-7
Focus mode switch
Focusing ring
To shoot in autofocus (AF) mode, set the focus
mode switch to AF.
To use only manual focusing (MF), set the focus
mode switch to MF, and focus by turning the
focusing ring.
2. Setting the Focus Mode
zQuickly turning the focusing ring may result in
delayed focus.
zThe lens’ focusing ring is electronic.
zIt is possible to set cameras that support
electronic fulltime manual focusing to manual
focusing when the camera is in the operational
mode. However, the camera settings need to be
changed.
zWhen AF operation is set to One-Shot AF,
manual focus is possible after autofocusing
has been completed by continuing to press the
shutter button halfway (electronic manual focus
function). However, the camera settings need to
be changed.
zWhen movie recording, the AF speed will be
slower than the still photo shooting mode. It is
possible to adjust the AF speed on the camera
by setting Movie Servo AF to [Enable].
Please refer to the camera’s instructions for
details.

ENG-8
3. Zooming
To zoom, turn the lens’ zoom ring.
zBe sure to finish zooming before focusing.
Zooming after focusing can affect the focus.
zBlurring may temporarily occur if the zoom ring is
quickly turned.
The control ring can be assigned the functions
that are commonly used with cameras, such as
shutter speed and aperture settings.
Control ring
The click action of the control ring allows you to
have a sense of how much it is being turned.
Please refer to the camera’s instructions for
details on how to use the control ring.
zThere are cases in which the sound of control
ring operations may be recorded when shooting
movies.
zThe clicking sensation of the control ring can
be removed by the Canon Service Center.
(chargeable)
4. Control Ring

ENG-9
5. Lens Function Button (AF Stop Button)
In the default settings, the lens function button
serves as a AF stop button. You can assign
different functions to the button from the
[Customize buttons] section of the camera.
Please refer to the camera’s instructions for
details.
Lens function button
(AF stop button)
Use as a AF stop button
During autofocus operation, you can press an AF
stop button to temporarily pause autofocus, and
then release the button to resume.
Press an AF stop button to maintain a focusing
distance or to avoid focus search.
Press the shutter button while holding down an
AF stop button to shoot at that focusing distance.
zUseful when autofocus is operating mostly in
Servo AF.