As the first “big lens” built by Canon specifically for the mirrorless RF mount, the Canon RF 100-300mm f/2.8L IS USM has a lot of expectations to live up to, especially for motorsport photographers used to lugging around a big prime lens while trackside.

Does it hold up to those expectations? The team at Canon (CPS), so kindly let me test their latest flagship lens at Mount Panorama for a couple of days, during which I captured 6898 images with it so I could judge for myself. So let’s take a look.

And, yes, before you come at me for that opening remark, I am aware that the 400mm, 500mm and 600mm primes do exist as RF models. But the current versions are just the last generation of EF models adapted for the RF mount. Whereas the 100-300mm f/2.8L IS USM has been specifically created for newer mirrorless bodies.

What’s Good

Captured with the Canon RF 100-300mm f/2.8L IS USM + 1.4x Extender on Canon R3

Weight

Despite being a “big lens”, the Canon RF 100-300mm f/2.8L IS USM is not heavy. In fact, given it’s only 2.6kgs, instead of using a monopod, I used the lens all day handheld.

Mounted to a Blackrapid sling strap, I was able to carry it around for a full day trackside, as I would any of my other camera equipment, without any issues. Given the size of the lens, it sure must have looked odd carrying it in that fashion. But in terms of everything else, being able to use the lens handheld allowed me it allowed me to be more nimble with how I used the lens, particularly when panning, which I always do a better job of handheld than with a monopod.

I’m sure the built-in stabilisation, which is rated for up to 6 stops in combination with an IBIS system, also contributed to being able to use the lens successfully handheld.

Zoom Range

Another thing that the Canon RF 100-300mm f/2.8L IS USM has going for it is the versatility of the zoom range. Sure, 100-300mm doesn’t give you a lot of reach while trackside, but once coupled with an extender, particularly the 2x, you’ve got a lot of flexibility.

200-600mm is a very good range to live in for motorsport photography. Often, when using a 400mm lens and even a 500mm, you might find yourself a bit short, especially at bigger, more modern circuits. But there are also times when they are way too tight, like at street circuits. Given that I go to so many different styles of race track over the course of a year, my personal preference is to have the flexibility of being able to zoom and 200-600mm covers just about every situation you could find yourself in as a motorsport photographer.

What’s Not So Good

Captured with the Canon RF 100-300mm f/2.8L IS USM + 2x Extender on Canon R3

Filters

The biggest issue with the Canon RF 100-300mm f/2.8L IS USM is the ability to use filters with it, especially polariser in motorsport photography. Unfortunately, the lens lacks the ability to use a drop-in filter means you need to get a huge 112mm filter to mount on the front of the lens. Given that the 112mm filter size is not all that common, obtaining a polariser at this size is going to be particularly expensive. Even more so than drop-in filters tend to be.

Another thing to consider when using a CPL is that the lens hood doesn’t allow you to quickly and easily adjust your polariser. You either have to reach into the hood to rotate the CPL and make adjustments or remove the hood entirely, neither of which really isn’t that practical. At least with drop-in filters, there is a little dial on the filter that you can use to make quick adjustments.

Need For Extenders

The fact of the matter is that 100-300mm isn’t a focal range that is all that useful when trackside. 300mm at f2.8 in the garages is fantastic, but for the lens to hold its own while trackside, you will also need either a 1.4x or 2x extender as well.

In saying that, the Canon RF extenders are very good. The autofocus performance was similar with and without the extenders, even with the cars travelling at high speed towards me. Also, the image quality, particularly the sharpness of the photos, was, for the most part, consistent both with and without the extenders. However, it is an additional expense you need to consider if you are looking to use the lens in motorsport photography.

What’s It Like To Photograph Trackside With The Canon RF 100-300mm f/2.8L IS USM?

Captured with the Canon RF 100-300mm f/2.8L IS USM + 2x Extender on Canon R3

The first thing you notice when using the Canon RF 100-300mm f/2.8L IS USM trackside is the size. While I’ve mentioned the lens isn’t heavy, and it’s not really as big as the 400mm (f2.8 prime), it is still quite sizable. So, while you can use it handheld easily, you do lose that subtly of a smaller lens (like the 70-200mm) when trying to capture candid photos in and around the garages.

It’s also more bulk that you need to consider when moving in and around big crowds. Despite using the sling strap to carry the lens, I often found I was holding the lens to safely manoeuvre it as I made my way through the crowds, both behind the team garages and getting through spectator areas.

Otherwise, the 100-300mm is well balanced, even with an extender attached.

The inbuilt stabilisation system is extremely good. Even at 600mm with the 2x extender attached, I was still able to use the lens very easily handheld for static shots.

As you would expect if you are familiar with Canon lenses, the 100-300mm features three stabilisation modes, and I was able to pan at 1/100th with a fairly solid hit rate at 400mm (200mm + the 2x extender), all still handheld. If I get another chance to test the lens, I’ll definitely push the stabilisation system harder with some slower pans while still handheld.

Obviously, if you are more comfortable using a monopod, you could certainly do that successfully without any of the stabilisation.

The autofocus was super responsive. Even when shooting head-on in the high-speed sections of the track, the combination of the camera (a Canon R3) and Canon RF 100-300mm f/2.8L IS USM with the 2x extender attached were able to hold the car in focus with very few frames only slightly missing focus.

And other than a lack of polariser, the lens held its own (both in terms of focusing and image quality) in tricky light situations, especially the early morning back-lit shots.

The Competition

Captured with the Canon RF 100-300mm f/2.8L IS USM + 2x Extender on Canon R3

Canon hasn’t opened up the RF mount to third-party lens manufacturers, but that’s not to say that there isn’t some solid competition from Canon’s existing RF lens range.

At a quarter of the price (once you include the extender for the 100-300), the Canon RF 100-500mm f/4.5-7.1L IS USM Lens is still a very, very good lens. Obviously, it does have some trade-offs, but for the price, flexibility and image quality, it does make it hard to justify the extra expense of the Canon RF 100-300mm f/2.8L IS USM, especially having to buy an additional extender.

That said, I can still see the benefits of the 100-300mm “big lens”. While I haven’t had a chance to test it yet, in low-light situations, particularly night racing, being able to use the lens at 300mm at f2.8 has some obvious benefits. Even with the 2x extender, 600mm at f5.6 is still very usable in low-light situations. And it’s much cheaper than the 600mm f4 prime.

Conclusion

Is the Canon RF 100-300mm f/2.8L IS USM a good sports lens? Absolutely it is.

Is it that much better than the Canon RF 100-500mm f/4.5-7.1L IS USM Lens to justify the extra expense? That’s a tougher question. The 100-300mm, especially when coupled with an extender, is an extremely versatile lens with exceptional image quality and autofocus response. But is it four times better than the cheaper 100-500mm? That’s harder to quantify.

Check the latest pricing on the Canon RF 100-300mm f/2.8L IS USM at Adorama (US/International), Park Cameras (UK) or DigiDirect (Australia)