- Focal length and maximum aperture: 300 mm 1:4.
- Lens construction: 15 elements in 11 groups.
- Diagonal angle of view: 8°15'.
- Focus adjustment: Rear focusing system with USM.
- Closest focusing distance: 1.5m / 4.9ft.
- Filter size: 77mm.
Fixed focal length IS lens popularly used in wildlife and sports photography Compact L-series telephoto lens with an Image Stabilizer which compensates for camera shake with equivalent effect of a shutter speed two stops faster. Two Image Stabilizer modes are provided: Stabilizer Mode 1 (the same mode featured on the EF 75-300mm f/4-5.6 IS USM) and the new Stabilizer Mode 2 which steadies the image during horizontal or vertical panning.
The image stabilizer also functions when using the Extender EF1.4xII or Extender EF2xII to provide that elusive 600mm shooting capability