The XG-7 uses Minolta’s SR mount family (often labeled MC/MD). The simplest choice is to buy an MD or MC lens, since Minolta made many good ones and third-party lenses were also commonly sold in Minolta mount.

Some non-Minolta lenses can be adapted, but options are limited. Adapters have existed for mounts such as M42, T2, TX, and Adaptall, and some other lenses can be adapted indirectly via M42. In practice, though, there were never many adapters for Minolta SR/MD bodies, largely because demand was low.

Using modern lenses generally does not make much sense on this camera. Since the XG-7 is a manual-focus film body with an older mount, adapting newer systems is usually less practical than simply buying a native MD/MC lens. You’ll usually get better value and fewer compatibility issues by choosing a Minolta lens or an older third-party lens made in Minolta mount.