Hi, I would appreciate it if anyone could guide me step-by-step on how to check if an old manual-focus, zoom lens, in this case, a Carl Zeiss Jena MC Macro Zoom 28-70mm, still works. The problem: this particular piece of glass is attached to a broken Minolta XD7 (which means I cannot load a roll of film into the camera and shoot in order to find out). Having never handled 1970s-era automatic film SLR before, I looked into the viewfinder and saw split-circles type focusing aid. On the lens body, there are one aperture setting ring, one zoom ring and one focus ring. I need to make sure this lens is still in working order before I place an order for Minolta MD MC lens adapter for my E-P2. Many thanks.