Using older Minolta lenses

Great question. Most people assume that all Minolta lenses fit the Sonys because they are marketed as such. The truth is that the Minolta lenses that fit the Sonys are those with the A-type bayonet mount, which Minolta did not start producing until the mid 1980s. Before that, they were making MD/MC mount lenses (manual versus auto, if you're curious about the A versus M). Your xG7 uses the older M-mount lenses, which are NOT directly compatible with the Sony cameras. The lenses with the M mounts are often labeled with the name "Rokkor."

With that said, you can get an adaptor to make them fit. However, it gets complicated. Basically, the distance between the lens flange to the sensor is different on the newer A-mount lenses, so even with an adaptor you will not be able to focus on infinity without using other additions/ optical extenders et al.

If you do go looking for adaptors, you'll find two types. One has a glass element inside and tries to alter the focal length of the lens so that you can use infinity focus, but in the process it slows down the lens/ acts much like a teleconverter. The adaptors without the glass inside can only focus within a few yards (designed for close-up work only, since the infinity focus doesn't work).

I hope this helps. Let me know if you need further info!