Canon RF 24-240mm 4.0-6.3 IS USM

If we reviewed this lens during the early 2010s - thus before the era of image auto-correction - we'd have rated the Canon RF 24-240mm f/4-6.3 USM IS as ... trash. The resolution, distortion, and vignetting figures obtained from pure RAW files are all catastrophic at the wide end of the zoom range. However, this observation is a bit academic nowadays. This lens was certainly never meant to be used without image auto-correction, and this provides the framework in which we'll have to rate it. Fully corrected, the Canon RF 24-240mm f/4-6.3 USM IS can deliver very decent, maybe even surprisingly good, results. Typical for many lenses of this class, it achieves its best quality in the lower half of the zoom range. The resolution is decent at (the heavily corrected) 24mm setting with a very high center quality and a very respectable sharpness in the outer image field. There is a bit of field curvature, though. The quality is very even across the image field at 50mm and 100mm. Unsurprisingly the quality tanks a bit at 240mm. However, the critical center quality remains very usable, whereas the borders/corners suffer without being poor. If you are using a Canon camera with a 20-26mp sensor, the lens will be plenty sharp at all settings. A curiosity is the difference between 24mm images taken using JPEGs and RAWs (processed via Adobe ACR at least). Auto-corrected RAW files show a bigger field-of-view - which isn't ideal because the viewfinder shows the JPEG version. It's not a major issue but worth noting. The auto-correction didn't fully compensate for the extreme distortions at 24mm, but the remaining barrel distortion is mild and wouldn't bother you in most scenes. At other focal lengths, this is a non-issue. Auto-correction also does an excellent job with respect to vignetting - and that's also very much needed given the native characteristic. While the lens is certainly not aligned to shallow depth-of-field, the technical bokeh is actually pretty good. The same can't be said about sun stars, although let's be honest here - you can't have it all. The biggest optical issue may be a high risk of sub-par centering quality, which is a bit of a disease in this lens class for obvious reasons (the zoom ratio).

The RF 24-240mm f/4L IS USM is a versatile, compact and lightweight 10x zoom lens for the Canon EOS R full-frame mirrorless camera system. Featuring a Nano Ultrasonic Motor for smooth, precise and quiet continuous auto-focusing, Super Spectra coatings, 7 rounded diaphragm blades for smoother bokeh, a zoom lock switch to prevent lens creep, a switchable Focus/Control Ring, and image stabilisation offering a claimed 5-stop advantage, the Canon RF 24-240mm f/4-6.3 IS USM is certainly a versatile all-rounder.

The Canon RF 24-240mm is the first native super-zoom for the EOS R system, providing the convenience of a 10x range taking you from wide-angle to respectable telephoto. No need to carry multiple lenses nor waste time swapping them, not to mention reducing the risk of dust entering the body. Longer ranges often come with optical compromises, but in my tests the RF 24-240 performed respectably, delivering good results across the frame, throughout the range and even at the maximum apertures. Sure it’s not bitingly sharp or contrasty, but equally there’s no obvious aberrations at least on out-of-camera JPEGs. To be fair, Canon is performing some fairly substantial lens corrections behind the scenes, but most of us will have them applied automatically and be none-the-wiser in day-to-day use. Ultimately the RF 24-240 may lack the glamour and quality of the larger, heavier and more expensive pro lenses, but in practice it delivers solid performance with unrivalled convenience at a decent price. Recommended.