RF 600mm f4 or stay with Sigma 150-600? How much does a costly prime lens up your game? Do you get more keepers? Tell me your experience below! : r/ canon
Canon RF 600mm F4 L IS USM Lens Review
Canon RF 600mm F4 L IS USM Lens Review
Canon EF 600mm f/4L IS DO BR USM Lens Prototype Images and Details
The Canon EF 600mm f/4 DO BR lens rumored to be announced in late 2017 - Photo Rumors