Canon R lenses were held in the highest esteem by professional and discerning amateur photographers the world over for their unsurpassed excellence, unique optical design and precision engineering. Each lens produces the highest resolution, contrast, brilliance, and color fidelity. They are Spectra coated both internally and externally to insure maximum color and tone balance, greater light transmission, and elimination of flare. Superb optical performance, coupled with reduction in weight and design refinement made these lenses famed throughout the world.
Due to shorter flange focal distance, Canon R lenses cannot be adapted to Canon EOS digital SLR cameras (and any other digital SLR cameras), but they are adaptable to digital mirrorless cameras.