I’ve previously had the 500mm f4.5 ex dg when I used to be a Nikon user. Switched to Sony and used the 200-600 Sony but found the bokeh not to my liking and missed the f4.5. Thinking of switching to the sigma 500 f4 sport ( canon fit) and using the sigma canon to Sony adaptor. Anyone have experience with this? Would love Sony prime 400/600 but out of my budget!