Canon EF600mm f/4L IS III USM Instructions Manual page 27

18. Extenders (Sold Separately)
Use an extender EF1.4× III or EF2× III to shoot
a larger image of a subject. Lens specifications
when using an extender are as follows.
Focal length (mm)
Aperture
Horizontal
Vertical
Angle of view
Diagonal
Maximum magnification (×)
Attach the extender to the lens, and then attach
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the camera. To detach it, reverse the order.
Errors may occur if you attach the extender to
the camera first.
Extenders cannot be used more than one at a
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time.
If using an extender EF2× III, the maximum
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aperture is then f/8 and cameras that can
shoot using AF are limited. Please refer to the
camera's instructions for details.
When an extender is attached, the AF speed will
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become slower to retain proper control.
EF1.4× III EF2× III
840 1200
f/5.6 – 45 f/8 – 64
2° 30' 1° 40'
1° 40' 1° 10'
3° 2°
0.21 0.31
19. Extension Tubes (Sold Separately)
Use an extension tube EF12 II or EF25 II to get
closer to a subject and shoot a larger image.
Lens specifications when using an extension
tube are as follows.
EF12 II
Focusing distance range (mm)
Magnification (×)
EF25 II
Focusing distance range (mm)
Magnification (×)
MF mode is recommended for accurate focusing.
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Close distance Long distance
3757 29435
0.18 0.02
Close distance Long distance
3382 14187
0.21 0.05
ENG-26