Alongside the EOS R5 and R6, Canon has announced a brace of lenses, all in the short to long telephoto range. Filling out the ‘long’ end are one L-series zoom, and two innovative primes. Click through to learn more about the 100-500mm F4-7.1L IS USM and the RF 600mm and 800 F11 IS STM.

100-500mm F4-7.1L IS USM

Let’s start with the more conventional lens of the trio – the 100-500mm F4-7.1L IS USM, which first appeared in mockup form at events earlier this year (remember when we had events?) featuring 20 elements in 14 groups, this is a complex design, which incorporates six UD (Ultra Low-Dispersion) elements and one ‘Super’ UD element. These elements should help control chromatic aberrations.

(Relatively) compact

The 100-500mm is relatively compact when zoomed ‘out’ to 100mm (207.6mm / 8.2 in) but extends (to 297mm / 11.7 in) at 500mm. A torque adjustment allows you to make the zoom movement stiffer or looser as desired, and lock the zoom ring if required.

Canon is at pains to reassure users that despite its telescoping design, this lens is very well-sealed against dust and moisture. At 1370 g (3 lbs), the 100-500mm is far from a lightweight lens, but it’s only a couple of hundred grams heavier than the much faster RF 70-200mm F2.8L IS USM. The front filter thread is a very reasonable 77mm.

A removable tripod collar allows the lens to be mounted directly onto a tripod, in situations where hand-holding isn’t desirable or practical.

Close focusing performance

Considering its focal length range, the 100-500mm offers good close focusing performance, with a minimum focus distance of 0.9m at the 100mm end of the zoom, and 1.2m at 500mm. This should make it practical for conventional short-tele portraiture. The maximum magnification ratio of 0.33X is achieved at 500mm (full extension at 500mm shown in this image).

Autofocus is handled by dual Nano USM motors that can work independently of one another for fast and silent AF.

5 stops of IS

This is a stabilized lens, rated at 5 stops of correction on an EOS R. When mounted on an R5 or R6, Canon claims that total stabilization with its I.S.-enabled lenses should improve due to both in-body and lens IS systems receiving information from the others’ sensors.

This two-way communication is enabled by the fast protocols developed for the RF mount. Canon quotes as much as an 8 stop benefit with some lenses. Canon claims you can expect 6 EV of correction from the 100-500mm and R5/6 combination, and this is something we’ll be sure to test as soon as we can. There are three IS modes to choose from: standard, panning or active during exposure.

Compatible with RF 1.4X and 2X teleconverters

The 100-500mm is compatible with Canon’s new RF 1.4X and 2X teleconverters, but only at focal lengths of 300mm and longer. A locking mechanism prevents their use at wider focal length positions, where damage might occur to the lens’ rear element.

The RF100-500mm F4.5-7.1 L IS USM lens is scheduled to be available in September 2020 for an estimated retail price of $2,699. The RF Extender 1.4x and 2x are scheduled to be available at the end of this month for an estimated retail price of $499.99 and $599.99.

Canon RF 600mm F11 IS STM

Alongside the 100-500mm Canon unveiled two very unusual lenses, both of which employ collapsible mechanisms and DO – Diffractive Optics – elements in their designs, to reduce their size and weight. The first is the RF 600mm F11 IS STM. Canon claims that the use of a new material for the gapless dual-layered DO element allows for smaller and more cost-effective designs compared to the EF equivalents.

Compact and lightweight

The 600mm F11 IS STM weighs less than a kilo (930 g / 2.05 lbs), features a perfectly reasonable 82mm filter thread and measures only 200mm (7.9 in) when stowed. Considering its focal length, these figures are impressive. The DO optical technology certainly helps, but the main reason for its unusual compactness is an innovative retractable design.

Retracting design

Retracting / collapsing designs have been around for as long as photographic lenses have existed, and the basic principle (and benefit) has remained the same – extend and lock the mechanism when you need to shoot with the lens, and retract / collapse it when you don’t, for compactness. This isn’t possible with complex multi-element primes (let alone zooms) but for a long tele like the RF 600mm, where most of the glass is clustered together, in a design with a lot of empty space between groups, it becomes an option.

Retracting design

To unlock the 600mm’s extending mechanism, just turn the collar, and pull (or push) to put the lens into either the extended shooting position, or collapsed storage position. When extended, the lens measures 270mm (10.6 in).

Fixed aperture of F11

Another way of keeping this lens small is its fixed aperture of F11. This is the kind of aperture that traditionally, we would have associated with mirror lenses, which were a devil to work with on D/SLRs because of the dim viewfinder image associated with such a small working aperture.

However, on a mirrorless camera with a decent EVF, that’s much less of a concern, especially now that the Dual Pixel CMOS AF systems in Canon’s EOS R-series cameras can autofocus at working apertures down to F22 (which – not coincidentally – allows for these lenses to be used with the new RF teleconverters). Yes, F11 (and remember that’s fixed – you cannot stop down as there is no multi-bladed iris) is still a limiting aperture for exposure, but it’s a much more practical working aperture now than it would have been back in the days of SLRs.

Image stabilization and autofocus

The 600mm F11 is also equipped with an image stabilization system which can deliver up to 5 stops of stabilization. Canon did not claim an increase in performance when paired with the EOS R5 and R6 IBIS systems, and this makes some sense given the limited ability of IBIS systems to effectively stabilize very long focal lengths. Autofocus is handled by an STM motor, of the kind that has become common in Canon’s more enthusiast-centric lenses and those optics intended to be used for video, as well as stills. It’s not as fast – or usually as silent – as Canon’s Nano USM motors, but still quite effective.

Canon RF 800mm F11 IS STM

The RF 800mm F11 IS STM is a very similar lens to the 600mm, but it’s a little bigger, a little heavier and features a little more glass (11 elements in eight groups, as opposed to ten elements in seven groups for the 600mm).

Bigger and heavier (but still compact)

The 800mm is 35% heavier than the 600mm, weighing in at 1260 g (2.77 lbs). At 282mm (11.1 in) when stowed in its collapsed position, it’s about the same length as the 600mm is when extended. When the 800mm is extended to its shooting position, overall length increases to 352mm (13.8 in). That’s longer than a mirror lens would be, but very compact for a conventional 800mm.

Larger filter ring, longer minimum focus

The general ‘upsizing’ of the 800mm compared to the 600mm extends to the filter ring, which is a less traditional (and less convenient) 95mm. The IS system in the 800mm is only rated to four stops, too, compared to five in the 600mm (rated as per CIPA, measured on an EOS R body). The minimum focus distance is longer, too, at 6m compared to 4.5m.

All of this probably makes the 600mm slightly more practical for most photographers, but there’s no doubt that 800mm can itch some places that 600mm can’t quite scratch. We suspect that both lenses will be a hit with fans of bird photography.

The RF600mm F11 IS STM and RF800mm F11 IS STM lenses are scheduled to be available at the end of July 2020 for an estimated retail price of $699.99 and $899.99, respectively.