Vivo officially launched its latest flagship smartphone, the X300 Ultra in China. Vivo says its new phone features Vivo’s best-ever suite of cameras and photography features, and the company promises that the X300 Ultra redefines mobile imaging for still photography and video. The company comes out swinging, saying that the X300 Ultra is “designed for professional photography.” Like prior high-end Vivo smartphones, the new X300 Ultra features Zeiss optical technology, collectively called the “Zeiss Master Lenses Collection.” Out of the box, the X300 Ultra has three rear cameras, which can be expanded via optional Zeiss add-on lenses. PetaPixel previewed these…