We love a good 24-70mm lens and the Canon RF 24-70mm f/2.8L IS USM is a shining example. Versatile, compact, and usually quite light, they’re probably the most essential piece of glass you’ll carry in your camera bag. Canon’s premium RF version of the standard 24-70mm focal length lens has the ability to shoot wider maximum apertures at up to f/2.8. We think it’s one of the best lenses for astrophotography you can buy, and if you own a Canon mirrorless camera it’s a brilliant lens for almost all situations. While astro purists will want something a little wider and a little faster, (maybe a 20mm with f/1.8 or even f/1.4,) this well-rounded lens will perform most nighttime photo tasks perfectly.
While many 24-70mm lenses across manufacturers are of a similar standard in terms of image quality, the Canon RF 24-70mm f/2.8L IS USM actually has a slight edge over direct competitors because it’s a touch smaller. It’s slimmer than the Nikon equivalent, for example, if ever so slightly heavier. As for the cost, though? Well, a quality 24-70mm lens with a max aperture of f/2.8 is always going to cost you more than $2000. The Canon currently weighs in at $2300 with most retailers.
If you’re interested in seeing what else is out there, we’ve also put together a guide on the best zoom lenses, the best lenses for astrophotography or if you need to save some cash but still get great glass there’s always the best used lenses for digital cameras. If you want to pick up a camera to go with it, our guides to the best cameras for photos and videos and best cameras for astrophotography are your best bet.
Canon RF 24-70mm f/2.8L IS USM lens review
Canon RF 24-70mm f/2.8L IS USM: Design
- Compact design
- Common filter thread size
- Relatively light
The Canon 24-70mm f/2.8L IS USM is fairly standard in terms of layout. Once snapped into the RF flange on any compatible Canon body you have a number of things to take note of in terms of design. There’s a focusing ring, a focal length ring, and an additional control ring nearest to the tip, which offers control over features like ISO and aperture. So, when you’re using this lens, and you’ve customized it, there are few reasons to take your hand off it while shooting. We prefer having a control ring further away from the body, as it’s easier to use, so bonus points to the Canon here.
Elsewhere on the lens’ black (with a narrow red highlight) barrel there are two switches that allow you to toggle between autofocus and manual focus or turn image stabilization on or off. We’d have liked to see an additional function button in this area of the lens to allow you more control over more used features, preferably a customizable one as we see on other premium lenses.
The 24-70mm f/2.8 handles all its zooming within the lens case itself, so this doesn’t change size telescopically like the 24-105mm f/4. While a very minor plus point, this means there’s no danger of over-balancing on a tripod once you’re set up. You can also use all compatible filters. The glass is flat at the far end of the lens, so there’s no issue using screw-on filters either.
Canon RF 24-70mm f/2.8L IS USM: Performance
- Excellent edge to edge clarity
- Good in low light
- Silent focusing
We tested the 24-70mm with the Canon EOS R under a variety of conditions. Given that we reviewed this lens in the fall we got plenty of wind and rain to test in but found a few clear skies in between.
As with all lenses in Canon’s premium range, you’re getting the best possible image quality here. There’s no noticeable loss of clarity from edge to edge on your images, the ASC coating means you minimize flare (unless you really want it), and overall photos come out incredibly sharp. Obviously, the camera body you use will have an impact on exactly how sharp, but this lens will happily pair with any EOS mirrorless, from the RP through to the R3. We pushed it to perform in low light, high contrast, and extreme color scenarios, and nothing managed to highlight any weaknesses here.
When it comes to focusing, the lens operates efficiently and silently, so if you’re shooting somewhere that requires absolute silence, there’s no whirring or noise to worry about. At night, it’s great for shooting wide-aspect astro, thanks to that 24mm focal width and the f/2.8 max aperture. We shot a few night scenes with it and we’re pleased with the overall effect. While you won’t pick out absolutely everything at f/2.8, it’s more than enough for impressive star vistas.
We tried to shoot the moon with this lens, just to test it out, but you’re never going to get a decent close-up with only a 70mm zoom. It manages to pick out the moon in wider landscapes, but that’s the extent of its lunar capabilities. We also tried it out with light trails and low-light indoor shots and it produced some good images here too.
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To really push the image stabilization we attempted a few handheld light trail shots, to see if we could retain clarity around the 1-3 second exposure mark. The results were very good, and while Canon’s claims that it can stabilize up to 5-stops will likely only apply to those with the steadiest of hands, we were impressed with what we got from the lens under these conditions.
Essentially, this lens performs exactly as you’d expect for the price. While it doesn’t do anything significantly better than more specialized lenses, it’s a great all-round performer, and a super useful thing to have in your kit bag.
Canon RF 24-70mm f/2.8L IS USM: Functionality
- Weather-sealed and dust repellant
- Easy to connect to camera body
- Lacking in extras
Again, while most lenses of this caliber are fairly similar when it comes to functions, there’s a checklist of essential features they all need. Having gotten drenched on several shoots we can confirm the lens is well weather sealed and you could probably use it out in the rain for a solid 30 minutes before really needing to try and dry it off. We wouldn’t recommend it but you shouldn’t be shy about it getting damaged in wet conditions.
Similarly, we tested to see whether or not the lens picked up dust easily. After letting it rattle around in the bag without a lens or rear end cap on for a while (naughty, we know,) we were pleased that there were very few spots or imperfections on our shots, meaning it picked up very little dust. Despite being light and compact, the 24-70mm f/2.8 is tough enough to withstand a few bashes and is a sturdy-enough piece of kit. It feels a little less robust than the Nikon equivalent, but certainly more capable than the Canon RF 24-105mm f/4 L IS USM lens, which we tested at the same time.
As for the rest of it — we’d like to have seen an additional function button or two on the lens itself. While we do have the additional control ring here, it would have been nice to be able to adjust a few other settings while holding the lens and shooting via the viewfinder. It’s hardly a deal-breaker, but feel it is nice to have.
If we’re nitpicking, we think the focusing rings feel a little loose, which means we got slightly less control when it comes to smaller adjustments. The torque on focusing rings really is a matter of preference, but these felt a little too loose for our liking. It’s such a minor point, though, and we quickly acclimatized to shooting with them.
Should I buy the Canon RF 24-70mm f/2.8L IS USM lens?
If you have the money, and you’re looking for the best generalist lens you can get for the Canon system then yes, you should buy this one. While it’s an expensive lens, it’s a beautiful one, and it’ll serve you so well under a variety of conditions. It isn’t a specialist lens for astro but it’s something you’ll use day-to-day and it can definitely handle itself in low light.
We love how small and light it is – you’ll have no problem shooting with this lens on all but the flimsiest of tripods (and if you’re spending $2300 on a lens, you maybe shouldn’t be shooting with a $40 tripod, right) – and it’s perfect for travel, especially with the weather sealing and dust-repellent coating. While it’s all about the performance, we’d like to have seen a few little extras for the money, but they’re far from essential.
If you’re searching for the perfect astro lens, this isn’t it. It’s a workhorse zoom that’s just as happy in bright sunlight as shimmering starlight. For something more specialized, we recommend the Canon RF 15-35mm f/2.8 lens instead.
If the Canon RF 24-70mm f/2.8L IS USM isn’t for you
The better option for pure astro and landscape shooters on Canon mirrorless cameras is the Canon RF 15-35mm f/2.8. It’s perhaps not perfect, as it ‘only’ gets as wide as f/2.8, but it’s a finely tuned piece of astro glass. If you need something EF mount for a DSLR though we’d opt for the Canon EF 16–35mm f/2.8L III USM which is just as classy.
If you’re looking to spend a little less, the Canon RF 24-105mm f/4 L IS USM is a good option. It’s more than half the price of the 24-70mm f/2.8, but lacks those crucial lower f-stops. With enhanced zoom, though, you’ll get far better shots of the moon with this one.
If you fancy even more zoom, while retaining your width, the Canon RF 24-240mm f4-6.3 IS USM is an exceptional lens. It isn’t really suitable for astro, as the variable aperture range moves from f/4 at its widest focal length to f/6.3 at its longest. It’s not quite as sturdy or well-weather sealed as the lens reviewed here either, but it’s great for moon images and it’ll handle landscapes nicely too.