Canon 400mm f/4.0 DO IS II USM lens review: Upgraded model punches above its weightBy Paul Carroll - Thursday April 09 2015 Lens Review
Canon has updated the original 400mm f4 DO lens using its new gapless diffractive optics construction, which promises high image quality. Read on to find out how well this new model performs.
Canon’s original 400mm f4.0 DO IS USM super-telephoto was a hugely innovative model at the time of its introduction in late 2000. The use of DO, or diffractive optics — a pair of elements each with an opposing Fresnel-like patterned surface —dramatically lowered both the weight and size of the lens compared with conventional designs of the same focal length and maximum aperture. Canon also claimed that the unique optical construction of the 400mm f4.0 resulted in lower chromatic aberration than models using fluorite elements.
The new model has similar weight and size advantages of the original (albeit with a slight increase), and adopts a new gapless construction between the two DO elements. These elements are also positioned deeper within the optical formula, which Canon claims reduces flare. Although not an L-series model, the new lens boasts a similar level of construction, with aspherical and UD glass, environmental sealing, 4-stop image stabilizer, and both SWC (Sub Wavelength Structure) and fluorine coatings.
Compared to the current 400mm f2.8, this new model is reassuringly compact, measuring just 5.04 x 9.16" (128 x 232.7 mm) and weighing 4.63 lb (2.1 kg). It is available to pre-order at $6,899.