Canon EF 200-400mm 4 IS USM

Canon EF 200‑400mm f/4L IS USM Extender 1.4× lens:

Key Specifications

• Focal length: 200-400 mm (with built-in 1.4× extender switched in: 280-560 mm)

• Maximum aperture: f/4 (at 200-400mm)

• Minimum aperture: f/32 (at 200-400mm)

• With extender engaged: f/5.6 max aperture (280-560mm)

• Lens construction: 25 elements in 20 groups (without extender)

• With built-in extender: 33 elements in 24 groups

• Diaphragm blades: 9 (rounded)

• Minimum focusing distance: 2.0 m (approx)

• Maximum magnification: 0.15× (without extender) / ~0.21× (with extender)

• Image stabilisation: Yes, claimed approx 4 stops of correction

• Filter size / drop-in: 52 mm (rear drop-in filter holder)

• Physical dimensions: maximum diameter 128 mm × length 366 mm

• Weight: approx 3,620 g (3.62 kg)

• Build: Magnesium alloy barrel, weather-sealed (dust & moisture resistant)

• Designed for full-frame (35mm) format, EF mount

Optical / Feature Highlights

• One fluorite lens element + four ultra-low dispersion (UD) elements to control chromatic aberrations.

• SWC (Sub-Wavelength Structure Coating) + fluorine coatings on front/rear to reduce flare/ghosting and aid cleaning.

• Built-in 1.4× teleconverter (extender) that is engaged via a lever on the lens — no need to remove the lens or attach a separate accessory.

• Internal zoom/focus: minimal change in length during zooming/focusing; good for professional use.

Use & Considerations

• Because of its constant f/4 aperture and long reach, this lens is well-suited to sports, wildlife, and other demanding telephoto use.

• Its weight (≈3.6 kg) and length (366 mm) mean that using a monopod or tripod is highly advisable for extended use.

• With the built-in 1.4× extender engaged, the focal length becomes 280-560mm with an aperture of f/5.6, providing extra reach without changing lenses.

• Filter considerations: The “52 mm drop-in” design means that standard front filters cannot be attached in the usual way; you use the rear holder. Useful in professional setups.

• Weather sealing and build quality make it reliable in challenging outdoor conditions.