Canon EF 400mm f/2.8L IS III USM EF400mm f/2.8L IS III USM Instructions - 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 Angle of view Vertical Diagonal Maximum magnification (×) EF1.4× III 560 f/4 - 45 3° 40' 2° 25' 4° 25' 0.25 EF2× III 800 f/5.6 - 64 2° 35' 1° 40' 3° 05' 0.36 OO Attach the extender to the lens, and then attach the camera. To detach it, reverse the order. Errors may occur if you attach the extender to the camera first. OO Extenders cannot be used more than one at a time. 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 (×) Close distance 2192 0.22 Long distance 13105 0.03 EF25 II Focusing distance range (mm) Magnification (×) Close distance 1946 0.30 Long distance 6330 0.07 OO MF mode is recommended for accurate focusing. OO When an extender is attached, the AF speed will become slower to retain proper control. ENG-26