Introduction

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Since the launch of the EOS R line in 2018, Canon has mostly concentrated its attentions on high-end RF lenses. And the lens we’re looking at here is likely to be one of the most coveted RF-mount optics, partly because of its classic portrait-friendly focal length and super-wide aperture, but also because Canon bills it as having the finest optical performance of any autofocus-enabled 85mm lens the company has ever released. Quite a claim.

Naturally, all of this goes some way to explain why the RF 85mm F1.2L USM is among the costliest lenses in the RF lineup. It’s considerably pricier than the EF 85mm f1.2 L II USM, which can also be used with EOS R-series bodies via an adapter, and if you’re happy to slum it with an F1.4 option then you’ll find many more cost-effective options from other manufacturers to choose from. Nevertheless, the RF 85mm should prove a tempting option for early EOS R-series adopters with an appetite for fast glass and pockets deep enough to satisfy it.

Key specifications:

  • Focal length: 85mm
  • Aperture range: F1.2-16 (In 1/3 EV stops)
  • Filter thread: 82mm
  • Close focus: 0.85m (2.79 ft.)
  • Maximum magnification: 0.12x
  • Diaphragm blades: 9 (rounded diaphragm)
  • Hood: ET-89 round-shaped hood (supplied)
  • Length / Diameter: approx. 103.2 x 117.3 (4.06 in. x 4.62in)
  • Weight: approx. 1,195g (approx. 2.63lbs)
  • Optical construction: 13 elements in nine groups

Features

Aimed primarily at portrait, fashion, wedding and event photographers, the RF 85mm F1.2L USM brings together a handful of RF-specific technologies with those seen previously in the EF line.

Despite its size and weight, the lens has been designed with just 13 elements in nine groups, although some of these are necessarily quite large. They include a single ground aspherical element to keep spherical aberration and corner softness from being a problem, and an Ultra Low Dispersion element positioned just ahead of it to help combat chromatic aberration.

Canon’s Blue Spectrum Refractive (BR) element greatly refracts shorter wavelengths, ensuring blue wavelengths focus at the same plane as longer wavelengths like red and green. This increases sharpness and reduces longitudinal spherical aberration, commonly seen as color fringing.

Longitudinal chromatic aberration (LoCA), typically seen as purple and green fringing in front of and behind the focal plane, respectively, is further controlled through the use of a Blue Spectrum Refractive (BR) element, something we first saw three years ago inside the EF 35mm F1.4L II USM. Its purpose is to refract blue light – or rather, short wavelengths that correspond with what we see as blue – to a greater degree than conventional optics would manage. By doing so, it’s better able to focus all wavelengths to the same point, which in turn helps to quash longitudinal chromatic aberration and increase sharpness at the focal plane. Quite how well it can do so is something we’ll be digging into later on in this review.

Helping to keep flare and ghosting down are Canon’s conventional multi-coatings, while a single application of the more advanced Air Sphere Coating (ASC) deals with ill effects from light passing either parallel or near parallel to the optical axis. Nine diaphragm blades, meanwhile, promise to keep the diaphragm round for nicer out-of-focus highlights.

The lens accepts 82mm filters at its front and can focus as close as 85cm (2.8 ft) away from the subject, which is a 10cm reduction on the previous EF 85mm f1.2 L II USM. Helping to make its price tag a little easier to swallow, Canon has thrown a deep round lens hood into the box, as well as a pouch to keep it all protected when not in use.

What about the Canon RF 85mm F1.2L USM DS?

The lens on test is joined by a slightly more costly (+$300) ‘DS’ variant, and while the it adheres to the same basic formula and optical design as the non-DS version, the ‘DS’ suffix denotes the presence of Defocus Smoothing technology. This is a new coating on two of its elements that’s said to help smooth out the edges of out-of-focus areas, which the company claims is more necessary here given the more severe correction for chromatic aberration. The effect is similar to some specialized lenses from Fujifilm and Sony that contain comparable apodization elements.

While potentially very useful to dedicated portrait photographers, the fact that the DS technology comes at the cost of up to 1.5EV stops of light transmission, and also produces images with slightly deeper depth of field than the non-DS version explains why Canon has decided to give the photographer the choice of both options.

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