- High-Performance Telephoto Zoom Lens
- Canon EF Mount
- Aperture Range f/4-32
- Built-in 1.4x Extender
- Three-Mode Optical Image Stabilization
- Ring USM Autofocus & Internal Focusing System
- Power Focus Mode for Smooth Focus Shift
- One Fluorite and Four UD Lens Elements
- Fluorine Front & Rear Lens Coating
- Highly Resistant to Dust and Water
c|net reviewed the Canon EF 200-400mm f/4L IS with built-in 1.4x extender, a lens that retails for $11,999. They attest a “superb image quality”, and write:
The Canon EF 200-400mm f/4L IS USM Extender 1.4X combines terrific optics, autofocus, and image stabilization with standout flexibility from a built-in telephoto extender.
You get you what you pay for with the Canon EF 200-400mm f/4L IS USM Extender 1.4X: superlative performance and flexibility.
The review has some samples shot with the 200-400mm.