The Canon RF-S 55-210mm F5-7.1 IS STM is only the third RF-S lens to be launched. Naturally, you can use EF and EF-S lenses on R-system cameras via an EF-EOS R mount adapter but that’s certainly not ideal. Apart from adding to the size and weight of the overall package, all-round performance tends to be rather better when using native RF and RF-S lenses.
