Canon RF 28-70mm F2.8 IS STM

Testers find it excellent in the low and middle part of the range, with a strong centre and very good outer field, and sharp across the frame by about f/5.6. At 70mm the centre holds up but the corners are poor wide open and need heavy stopping down. Raw files show near-black corners at 28mm f/2.8 and over 4% barrel distortion, with pincushion toward 70mm; correction cleans this up at some cost in corner noise. Lateral colour is moderate, and bokeh fringing at f/2.8 is mostly gone by f/4.

The STM autofocus is fast and quiet, and the IS is efficient if not exceptional. Testers like the size, weight and seals but not the retractable mechanism, the single shared ring or the extra-cost hood. Testers disagree on price: OpticalLimits calls it a decent but overpriced choice, while Digital Camera World counts the price as a strength. Both point to the similarly priced RF 24-105mm F4L as the main alternative, which Digital Camera World finds sharper with less distortion.

Owners mostly bought it as a light f/2.8 walkaround for R8, RP, R50 and R6-series bodies, and the low weight is the main reason they like it. Many say sharpness at f/2.8 to f/4 rivals the RF 24-70mm f/2.8L or beats the RF 24-105mm F4L, and they praise quick AF, effective IS and more background blur than expected for portraits, children and travel.

The common complaint is twisting the barrel out to 28mm before shooting, though most get used to it and like that there is no lock button. Others mention the high price, the extra-cost hood and the modest 0.24x magnification, and one portrait shooter sold it over ghosting when shooting into the light.