hen we first tested the Canon RF 100-500mm, we were a little underwhelmed by its autofocus speed on first-generation EOSvery good value for money but there’s no denying that it’s a big, heavy lens, whereas the Sigma 500mm prime is really weighty. The Tamron 150-600mm G2 feels a lot more manageable. The Canon EF 100-400mm is smaller and lighter than 150-600mm zooms and, while it doesn’t have such long telephoto reach, it’s a fine lens with a slightly faster aperture rating.
