Canon 400mm f4.0 DO IS USM II - 1931

Canon 400mm f4.0 DO IS USM II - 1931

What our Experts Think

• Lightweight super‑telephoto prime with diffractive optics (DO) for a much smaller, lighter 400mm lens than conventional designs, ideal for handheld use on long shoots.
• Excellent optical quality with gapless dual‑layer DO, aspherical, and UD elements for sharp images with strong contrast and controlled aberrations.
• 4‑stop image stabilization helps reduce blur from camera shake—very useful for field, wildlife, and sports work without a tripod.
• Weather‑sealed build and solid construction suit challenging outdoor conditions.
• Fast and quiet USM autofocus with full‑time manual focus override gives reliable focus performance.
• Compact for its class yet delivers true prime‑length reach with excellent handling compared to bigger f/2.8 counterparts.
• Variable bokeh character typical of DO optics—smooth but with unique rendering that may differ from conventional primes.
• Best in good light—wide‑open f/4 means lower light performance isn’t as strong as f/2.8 super teles

Q&A

Q1: What type of lens is this?
A: It’s a 400 mm telephoto prime lens with Diffractive Optics (DO) for Canon EF‑mount full‑frame cameras — designed for sports, wildlife, and long‑distance shooting.

Q2: What does “DO” (Diffractive Optics) mean?
A: Canon’s DO technology uses special optical elements to reduce size and weight compared with conventional super‑telephoto designs while maintaining excellent correction of chromatic and spherical aberrations.

Q3: What’s the aperture and optical performance like?
A: It has a constant f/4 maximum aperture with a 9‑blade diaphragm and includes UD and aspherical elements to deliver sharp, high‑contrast images across the frame.

Q4: Does it have image stabilization and autofocus?
A: Yes — built‑in 4‑stop optical Image Stabilization reduces shake for handheld shooting, and USM ensures fast, smooth autofocus with full‑time manual override.

Q5: What’s its close‑focus capability?
A: The minimum focus distance is ~3.3 m (10.8 ft) with a magnification of ~0.13× — suitable for distant subjects but not true macro.

Q6: How is the lens size and weight?
A: It’s compact and relatively lightweight (~2.1 kg / 4.6 lb) for a 400 mm prime, making it more portable than many other super‑telephoto lenses.

Q7: Is the build quality professional‑grade?
A: Yes — weather‑sealed and robust construction stands up to demanding outdoor use.

Q8: What types of photography benefit most?
A: Ideal for wildlife, birds, motorsports, action, and outdoor sports where reach, sharpness, and lighter weight are priorities.

Q9: Can it be used with teleconverters?
A: It’s compatible with Canon EF teleconverters for extended reach, though performance varies with teleconverter used.

Maintenance Tips

• Clean optics carefully: Use a blower and microfiber cloth; avoid direct contact with the lens glass.
• Protect lens elements: Always use lens caps, UV/filter, and lens hood to prevent scratches, dust, and flare.
• Store properly: Keep in a dry, padded case with silica gel to prevent moisture, fungus, and dust buildup.
• Handle zoom, focus & IS gently: Operate rings smoothly; never force mechanisms.
• Avoid extreme conditions: Protect from rain, dust, heat, and humidity.
• Inspect regularly: Check for dust inside, mechanical wear, and IS functionality.
• Transport safely: Use a dedicated lens case or tripod collar for safe handling of the heavy lens.