Here is a Canon EOS R50 review. The EOS R50 is one of the more…
Canon EF 200-400mm f/4L IS 1.4x Lens Sample Shots (lots of them, and the lens is available for rent)

Lenstip has 36 sample pictures shot with a Canon EF 200-400mm f/4L IS 1.4x (Amazon | Adorama | B&H) lens and a Canon EOS-1D X. Thanks Mark.
As much as this is a highly regarded lens, it is not inexpensive ($11,799). Hence, someone might be interested to rent the EF 200-400mm f/4L IS 1.4x at Borrow Lenses (click here).
Canon EF 200-400mm f/4L IS 1.4x specs:
- High-Performance Telephoto Zoom Lens
- Canon EF Mount
- Aperture Range f/4-32
- Built-in 1.4x Extender
- Three-Mode Optical Image Stabilization
- Ring USM Autofocus & Internal Focusing System
- Power Focus Mode for Smooth Focus Shift
- One Fluorite and Four UD Lens Elements
- Fluorine Front & Rear Lens Coating
- Highly Resistant to Dust and Water
Canon EF 200-400mm f/4L IS Extender 1.4x
Amazon | Adorama | B&H or rent it at Borrow Lenses