I try to support the camera when at all practical. I cannot even imagine shooting the equivalent of a 600mm telephoto lens on a medium format camera. My current lenses and supports are heavy enough, especially after walking a few miles over hilly ground! Much of my close-up shooting is done hand-held with the 200mm micro-Nikkor and SB-900, but the flash duration is acting as the effective shutter speed. The 300mm f/4 AF-S is often used for the shier subjects. Imagine these lenses scaled up to the sizes necessary to fill the frame of a medium format camera. My D200 and D800E are heavy enough with the telephotos, flash brackets, and speedlights. I toyed with the idea of trying MF equipment after I retired, but then considered my shooting style and the weight involved if everything was scaled up.