The 1.4x EX converter is placed between the lens and the camera, and it allows the photographer to use the 70-200mm f/2.8 lens as a 98-280m f/4 lens, and the 300mm f/2.8 lens as a 420mm f/4 lens; the high optical performance is maintained and the AF speed is not affected.
- Lens construction: 5 elements in 3 groups
- Focal ength: 1.4x that of a master lens
- Aperture coupling range F2.8 - F32
- Reproduction ratio 1.4x that of a master lens
- Dimensions 68.5 x 19.5mm
- Weight 143g