Leaderboard

Supposedly Sigma plans to make their 100-400mm f/5-6.3 DG DN OS Contemporary lens availablle in X-mount soon. According to various reviews (eg, Dustin Abbott), the Sony E-mount version of that lens is optimized for the long end and out-performs the Canon RF lens at 400mm. I have used the XF100-400, the Sigma 150-600C (EF+Fringer) and XF150-600 on the X-T4 and boht of the 150-600 lenses far outperform the XF100-400 at 400mm. The Sigmas was excellent, but too heavy for me to hand-hold and sometimes struggled with autofocus. The XF150-600 is superb all around and doesn't lose much to faster lenses because it is as sharp wide open as stopped down across its entire range.