Sony Alpha 7R IV
The Sony A7R III combines almost everything professional photographers could wish for: A high-resolution 60 megapixel CMOS sensor (plus high-res shot) with solid noise performance, built-in 4K recording, an even sharper viewfinder and all combined in a rugged housing with an optimized AF-joystick and a larger grip than its predecessor.
The Sony Alpha 7R IV still features two SD card slots, but unlike the third generation, both slots now offer support for fast SD memory cards with UHS-II interface. Professional photographers who want to save the same photo or video material on both cards (simultaneous photo/video recording) should ideally use two identical cards.
We generally recommend SDXC memory cards (64GB and more) with an UHS-II-interface and SD Speed Class from U3/V30 or above, if you're using a Sony A7R IV. Especially during burst shooting in full resolution (RAW), an UHS-II enabled SD card offers a significant advantage in terms of speed.