EF 70-300mm f4.5-5.6 DO IS USM
The EF 70-300mm telephoto zoom features a triple-layed diffractive optical element (DO), enabling Canon to produce a 70-300mm lens less than 10cm long.
The new EF 70-300mm zoom is the first DO lens to be released by Canon since the award-winning EF 400mm f4 DO IS USM was introduced in late 2001. Use of the new three-layer DO lens drastically reduces the overall length and weight of the lens system, increasing the refractive power of each lens element and reducing the spaces between elements. Chromatic aberrations normally associated with increased compactness are corrected by positioning the three-layer type DO lens on the front lens side. This, coupled with the correction of spherical aberration through the use of aspherical surfaces, delivers high image quality and high levels of resolution and contrast, rivalling the performance of Canon’s legendary L-series lenses.
The EF 70-300mm features a zoom ring locking mechanism, locking the lens at its shortest total length. This helps to protect the lens from potential damage by preventing the zoom elements extending under their own weight.
The lens incorporates Canon’s Image Stabilisation (IS) technology. This compensates for approximately three steps in speed without any perceptible increase in image blur when shooting static subjects or panning with a hand-held camera. For example, shooting at 1/125 second without the IS switched on gives similar results, in terms of blur from camera shake, as shooting at about 1/15 Second with the IS activated.
During major movement in a single direction, IS Mode 2 automatically determines that the movement is intentional panning and halts correction in the relevant direction.
The system also detects the lack of movement or vibration which indicates the use of a sturdy tripod and turns off the IS to avoid over-correction.
A rear-focusing ring type USM, high-speed CPU and new AF algorithms combine to give the lenses extremely fast auto-focusing.
Full-time manual override is featured, removing the risk of damage to the autofocus mechanism during manual focus.
In the 70-300mm lens, appropriate refractive and DO elements are combined to realise a similar high performance. The lens incorporates a near circular aperture diaphragm for beautifully pleasing background blur (bokeh).
Working with EOS
The drive pattern of each lens is tailored to suit the latest EOS cameras, extracting maximum benefit from the wide maximum apertures.
EOS magazine, March 2004, page 64
Construction (elements/groups): 18/12
Diagonal angle of view: 34° to 8°15’
AF drive system: Ring USM
Manual focusing: Enabled with focus mode switch and focusing ring (full time manual focusing)
Focusing range: 1.4m to infinity
Maximum magnification: 0.06x (wide); 0.19x (tele)
Minimum aperture: f32 to f38
Aperture blades: 6 (circular type)
Filter diameter: 58mm
Diameter x length: 82.4 x 99.9mm
Lens hood/lens cap: ET-65B/E-58U
Lens case: LP1116
Lens Extender EF: not compatible