Canon has introduced updated versions of two of its professional telephoto lenses, in the shape of the EF 300mm f/2.8 L IS II USM and the EF 400mm f/2.8L IS II USM. Both feature completely new optical designs, along with lighter weight construction employing magnesium alloy and titanium. Sub Wavelength Structure coatings are employed to minimize flare, plus water-repellant Fluorine coatings on the front and rear elements. A new IS mode has been added that activates stabilization only during exposure, alongside a 'Power Focus' mode for video shooting. The upgrades are rounded off by the addition of repositionable AF stop buttons and a choice of tripod mounts.