RDM5546
Senior Member
The central image sharpness is excellent wide open throughout the zoom focal length range. The corners are slightly less sharp wide open but actual very good IMO. When used in conjunction with the R5 and the RF 25-105mmf4L the EF 70-300 L can add considerable lens focal length reach in a very high quality short (5.5") rugged weather sealed lens that is easy to pack for travel upright in a backpack. Physically longer Canon white series L lenses (like the EF 100-400f4-5.6L) require much more space from the laying down of the lens in your bag. The threesome of R5, RF24-105f4L and adapted EF 70-300mmf4-5.6 may used to make a high quality rendering, moderately compact, weather sealed, rugged travel kit. An RF 24-70mmf2.8L lens may be substituted RF 24-105mmf4L should the travel kit benefit from the better low light operation that the f2.8 aperture provides.