What We Like
+Constant f/2.8 aperture throughout entire zoom range – first and only 100-400mm equivalent lens with this brightness
+Exceptional 5-axis Sync IS providing up to 7 stops of stabilization for handheld telephoto shooting
+Remarkably lightweight at 1,075g without tripod adapter, with excellent balance and portable design
+Excellent image quality with minimal chromatic aberration, distortion, and edge-to-edge clarity
+Versatile 0.78m minimum focusing distance enables macro photography at 0.5x magnification without teleconverter
+High-speed autofocus supporting 50 fps continuous tracking for wildlife and action photography
Worth Knowing
−Premium pricing at $3,699 USD, significantly higher than competing telephoto options
−Light fall-off in corners at maximum f/2.8 aperture requires stopping down 2+ stops to fully eliminate
−Bokeh quality becomes fussy in some backlit scenarios, with polygonal edges when stopped down
−Macro performance with dedicated macro lenses falls noticeably short compared to dedicated macro optics