Canon RF 15-35mm F2.8 L IS USM

Lab tests put the centre in excellent shape across the range from f/2.8, with very good results once stopped down. The weak point is the extreme edges at 15mm wide open, which are soft and improve only partly on stopping down; at 35mm the corners are good at f/2.8 and excellent from f/5.6. Lateral colour fringing is low throughout, and flare is well resisted, though not immune.

Raw files at 15mm show very heavy vignetting, more than 4 EV at f/2.8, and corners stay darker even after in-camera correction. Measured barrel distortion at 15mm is moderate and turns into mild pincushion further in. Autofocus is fast and silent. The stabiliser helps in low light but falls short of the rated 5 stops in testing. Size, weight and the high price are the usual reservations, though one test rated its price-to-performance highly given the lack of RF alternatives.

Owners describe fast, quiet focusing and sharp images, and several who moved from the EF 16-35mm f/4 or f/2.8 III say the RF version is the one they now use most. Landscape and astro shooters like the 82mm front filters and use it for star fields, and one reports sharp handheld shots at 1/4 second with lens IS and IBIS. Wedding and architecture photographers say it reliably does the job.

The complaints are size, weight and price. Some owners say it is front-heavy and slippery on small bodies, and a few say the RF 14-35mm f/4 or RF 16mm f/2.8 would have suited them better. Others mention dark corners wide open and soft 15mm corners, and one returned a copy that was soft at f/2.8.