Canon RF 85mm f/1.2L USM DS Lens Review

The Canon RF 85mm f/1.2L USM lens has already been fully reviewed and found to be Highly Recommended. We now look at a significant variant, the Canon RF f/1.2L USM DS, labelled as “Defocus Smoothing”. This is achieved utilising an optical effect described as "apodisation". Lens elements are used that show progressive darkening towards the edges and this results in smoother defocusing of out-of-focus areas, in other words, enhanced bokeh effects. This also results in a slight loss of speed over the marked f stops, so the actual light transmission of the f/1.2 lens becomes T2.2, a loss of just over 1 stop. The DS lens is more expensive than the standard version, so let's see if this can be justified and also how the apodisation affects the visual properties of the lens. The standard version of the lens has also been available again for this review, so some comparisons can be made. Let's fire up the 24.1MP Canon R3 and see what there is to be discovered.

Canon RF 85mm f/1.2L USM DS Handling and Features

The lens may look large on the EOS R3, but it is mostly the bulk of it rather than the weight, which is in fact a reasonable 1195g. Balance is front heavy (all of that glass will be heavy) but ergonomically it all works together well enough.

Starting our tour of the lens, a generously sized bayonet lens hood is provided. There is a locking catch and the whole is secure. Within the bayonet, fit is a standard 82mm filter thread and a huge front element, as we might expect. This element is fluorine coated, as is the rear element, to repel moisture and grease. The whole lens is dust and moisture-resistant.

The first control ring can be programmed for various functions. It is very slick in operation, with light but positive click stops provided. The first choice is selecting whether or not the ring is always live, or whether the photographer prefers it to only be active when the shutter release is half depressed. The ring can control exposure compensation, aperture, shutter speed or ISO. It can also be switched off.

Behind this is the manual focus ring, again very smooth, and electronic in operation. Focusing is down to 0.85m, or 2.79 feet, with a maximum magnification of 0.12x.

Finally, there are two switches. The first is the self-explanatory AF/MF selector and the second is the focus limiter. The choice for focus is either full range or from infinity down to 1.5m. In fact, the USM focusing is very fast and extremely accurate, a very important point considering the minuscule depth of field available at f/1.2.

Optical construction is 13 elements in 9 groups. There is a UD (Ultra Low Dispersion) element and also a ground aspheric glass, more difficult to manufacture and more expensive than the more common moulded aspheric. Canon's Blue Spectrum Refractive (BR) optics are utilised to remove any colour fringing. The diaphragm consists of 9 blades, aiming for a rounder aperture and therefore improved bokeh.

So far the lens is pretty much identical in construction to the original, but the DS designation indicates that two of the elements are treated with vapour deposition coatings that create the apodisation effect. This effect will be most obvious at open aperture and will reduce steadily as the lens is stopped down. The other effect is on lens speed, that is, the brightness of the transmitted light. The darkening results in a loss of speed of around 1 and one-third stops, so although f/1.2 will still be f/1.2 as regards depth of field there will be a reduced transmission value, so metering will be based on T2.2 – some bodies will need firmware updates to ensure that the metering compensates accordingly.

Handling is of course just as with the original version of the lens, absolutely hazard-free, except for it being very bulky. There is no IS, but this may well be built into the camera body.