Canon RF 100-300mm f2.8L IS USM review so far
Written by Gordon Laing
The Canon RF 100-300mm f2.8L IS USM is a high-end telephoto zoom for the EOS R mirrorless system, aimed at indoor or close-range sports, or where you need a little more reach than a 70-200, like at red-carpet events.
This is an unashamedly high-end lens designed for working pros or well-heeled enthusiasts with a price tag to match: brace yourself, as you’re looking at spending around $9,500 USD or £11,500 GBP, but as you’ll see, this actually isn’t unusual for this kind of lens, at least from the major camera companies. Canon let me try out a pre-production model to bring you the basics in the video below, and once I’ve fully tested a final production sample, I’ll link to it here. If you prefer to read the highlights, keep scrolling.
Announced in April 2023, it represents a new focal range for Canon, delivering the 300mm f2.8 specification beloved of sports photographers, but with the added flexibility of a 3x optical zoom.
As such, it not only becomes the mirrorless replacement for the EF 300mm f2.8L II from 2011, but also arguably an alternative to the EF 200-400mm f4, especially as the new lens will work with Canon’s existing RF teleconverters to extend its reach. Add the RF 1.4x TC and the 100-300 2.8 becomes a 140-420 f4. Add the RF 2x TC and it becomes a 200-600mm f5.6, which could be useful for more distant sports or even wildlife.
Mount this combo on a cropped body like the EOS R7 and the reach becomes equivalent to 960mm, and Canon claims the optical quality is not only better than the old 300 2.8, but uncompromised when using teleconverters.
A 100-300 2.8 may be a new proposition for Canon, but isn’t dissimilar to Nikon’s AF-S 120-300mm f2.8, an older lens for DSLRs which still costs around ten grand. And lest we forget the old EF 300 2.8 and 200-400 lenses still command prices of around six and 11 grand respectively, so maybe the new 100-300 2.8 isn’t as expensive as it first sounds. No hang on, of course it is, but my point is this is the kind of price you’ll be paying for a professional super-telephoto, at least from the likes of Canon and Nikon.
Note Sigma previously offered a more affordable 120-300 f2.8 for various DSLR mounts, but it was considerably heftier. If you’re on a tighter budget though, it could be worth tracking one down.
Ok it’s time for a line-up to put the new lens in perspective. On the far left is the RF 70-200 f2.8L, alongside the RF 100-500, both looking relatively compact in comparison to the others, and remember the latter only works with teleconverters for part of its range, while the former can’t use them at all.
In the middle is the old EF 300mm f2.8L Mark II, and to its right is the new RF 100-300mm f2.8L, where you can see it’s obviously longer, albeit not quite as long as the EF 200-400 on the far right. Crumbs, that’s over 30 grand of gear right there.
Of course the more detailed comparison you want to see is between the old EF 300 2.8L II, seen here on the left and the new RF 100-300 f2.8L on the right.
Both lenses share the same 128mm maximum diameter, but at 323mm, the new zoom is 75mm longer than the old prime. While this is the size you’ll need to accommodate in your bag though, Canon’s reduced the length of the supplied hood.
So here they are with their hoods attached, where you’ll see the working length has now become quite similar, indeed almost identical if you add the EF to EOS R adapter to the prime on the left to use it on a mirrorless body.
In terms of weight, you’re looking at 2.4Kg for the old prime versus 2.59Kg for the new zoom, so just 190g difference which you’ll barely notice in use. Indeed it’s worth noting the new zoom on an R3 body is a lighter combination than the old lens on a 1Dx Mark III.
The RF 100-300 has three rings, a smooth motor-assisted manual focusing ring, followed by a generous zoom ring which operates internally, so no extending barrel here. Towards the end of the barrel is the usual customisable control ring of higher-end RF lenses. This clicks as standard, but you can have it declicked for smooth and silent operation at a Canon service centre; shame there’s not a simple switch to declick it.
Like other super-teles there’s a selection of switches, starting with Lens Function which you can use to pre-program a set distance like a goal or nesting branch.
This is followed by switches to limit the distance from 6m to infinity, select manual or autofocus, enable the optical image stabiliser, and choose the actual stabilisation mode.
Canon quotes the IS system as delivering up to 5.5 stops by itself or up to six when used with a body sporting IBIS.
Like other large lenses, the RF 100-300 features a built-in collar which allows the barrel and body to rotate while it’s mounted on a tripod. 90 degree intervals are felt with a tactile click, while a thumbscrew can lock it in place.
As I turn the barrel you’ll notice the four buttons around the outer end of the barrel as well as one more near the mount, all sharing the same programmable function, set to AF Hold as default.
The lens is also supplied with a tripod foot, albeit lacking a dovetail to slide directly into a tripod clamp; why this isn’t standard I don’t know, but you can still use the foot as a handle to carry the lens, as well as swapping it for one of a different length if preferred.
Eagle-eyed Canon spotters may have noticed that unlike the old EF 300 2.8, there’s no longer the option to use drop-in filters on the new zoom, forcing you to instead invest in 112mm filters which screw in the front.
In another departure with many super-teles, the 100-300 also dispenses with the sliding padded cover in favour of a simple plastic cap. While this is a change from older or longer lenses, I’m personally not that bothered, and you can still securely stand the lens up on its rubber-tipped hood. Oh, and a padded pouch bag is also supplied.
As a high-end L-lens, the 100-300 is of course weather-sealed to the same standard as previous Canon super-telephotos, including a rubber grommet at the mount. Note the white coating on the barrel is now more effective under hot conditions than the old 300’s coat.
Wrapping up the specs are an optical construction with 23 elements in 18 groups, a nine-blade diaphragm system, and a closest focusing distance of 1.8m at all focal lengths, delivering a maximum magnification of 0.16x when set to 300mm.
Focusing is courtesy of dual nano USM motors and an overlapping floating design. The lens also supports focus breathing compensation and minimises focus shift when zooming, albeit not officially parfocal.
Just before wrapping-up, one last physical comparison, this time from the side, with the new RF 100-300 at the bottom and the old EF 300 prime at the top. And now both lenses with their hoods and an EOS R3 mounted.
Let’s now switch the EF 300 at the top for the old EF 200-400 zoom, before adding the hood and again the R3 via an adapter.
Next the RF 400 2.8 super-tele prime lens which can mount natively to the EOS R3, although I couldn’t fit the hood into the frame.
And finally, the new RF 100-300 in various configurations, first the lens by itself, now with the supplied hood attached, and next with the EOS R3 body mounted.
And for good measure now let’s add the RF 1.4x teleconverter which turns it into a 140-420mm f4 zoom, and finally with the RF 2x teleconverter, which turns it into a 200-600mm f5.6.
And that’s all I can tell you until I test a final production sample, which again I’ll link to here when it’s ready. Until then I’d love to hear what you think of the new lens, and Canon’s approach of trying to do something a bit different with its statement lenses.
After all while most sports photographers would probably have been happy with a mirrorless update of the 300 2.8, the addition of a zoom makes it much more flexible, kind of like a 70-200 on steroids. If it also lives up to Canon’s claims of out-performing the original 300 2.8, it’ll undoubtedly become a common sight at the sidelines of sporting and red-carpet events.Check prices on the Canon RF 100-300mm f2.8L IS USM at B&H, Adorama, WEX UK or Calumet.de. Alternatively get yourself a copy of my In Camera book, an official Cameralabs T-shirt or mug, or treat me to a coffee! Thanks!