Canon Adds To Growing RF Lens System
With an EOS R series sports camera coming, Canon has added the mandatory prime supertelephotos to its RF-mount lens line-up. There’s also a second RF macro lens and this trio bring Canon’s RF mount system up to 22 models.
The RF 400mm f/2.8L IS USM and RF 600mm f/4.0L IS USM are essentially the same lenses optically and mechanically as the EF models, but with the mount end re-engineered with an extension tube to ‘correct’ for the shorter flange back distance of mirrorless bodies. Presumably, given the low volume sales of these supertelephotos, Canon has chosen not to design completely new lenses so neither have the dedicated multi-function control ring that is a feature of all the other RF models. However, the manual focusing collar can be used as a control ring with some EOS R series bodies. There have also been upgrades to autofocusing systems and control CPUs to take advantage of the capabilities delivered by the RF mount and the mirrorless camera configuration. In particular, the RF 400mm and 600mm will operate at the EOS R3’s promised 30fps shooting speed with continuous AF adjustment. Both have more powerful AF drives. They will also be able to support upgraded subject detection and tracking functionality. Additionally, both lenses allow for aperture adjustment in one-eighth stop increments. The optical image stabilisation gives up to 5.5 stops of correction for camera shake, but there’s no Co-ordinated Control IS tie-up with the IBIS systems in the R6, R5 and forthcoming R3 to give an extended range. Both the RF 400mm and 600mm share the same optical construction comprising 17 elements in 13 groups, including one Super UD type and two fluorite types. They also have both Canon’s Super Spectra Coating (SSC) and Air Sphere Coating (ASC) antireflection multi-coatings.
The new RF 100mm f/2.8 Macro IS USM is an interesting lens for a number of reasons, the first being its maximum magnification ratio of 1.4:1 or 1.4x life size, which is a world first. This is made possible by the shorter flange distance of the mirrorless camera configuration and also a ‘floating’ internal focusing system. The minimum focus distance is 26cm, but this translates into a minimum working distance of just 8.6cm.
The optical image stabilisation gives up to five stops of correction, but this is increased to eight stops in conjunction with in-camera stabilisation. Additionally, there’s a ‘Hybrid IS’ mode that engages automatically at the closest focusing distances – when the effectiveness of image stabilisation is diminished anyway – and corrects for both horizontal and vertical shifts as well as for angular movements of tilt and pan. Focusing is performed by Canon’s Dual Nano USM system for speed and quietness, and Canon claims a 50% improvement in the suppression of focus breathing compared to the EF-mount 100mm Macro, which is particularly important when using focus stacking.
The RF 100mm Macro lens boasts a f eature called Spherical Aberration Control, which has a dedicated ring that adjusts the softness of out-of-focus effects – or bokeh
– in the background and/or foreground. The SA control ring operates over a range of plus/ minus four steps. There’s also the standard RF lens multi-function control ring, which can be set to adjust the aperture, shutter speed, ISO or exposure compensation. Other features of the new macro lens include magnesium alloy barrel tubes with weather sealing, a fluorine coating on the exposed surface of the front element to help repel moisture and grease, and a nine-blade diaphragm (for more rounded out-of-focus effects).
The RF 400mm and 600mm supertelphotos and the RF 100mm Macro will be available in Australia in July.