Could you please update us your full Minolta lens model ?as Minolta has MD MC and AF mount, K&F Concept MD-M4/3 is suitable for: Lens: Minolta MD MC Mount lens(not for Minolta AF mount: KF06.157) Camera: Micro 4/3 (MFT) mount mirrorless camera like Olympus PEN, OM-D series, Panasonic Lumix DMC-G1, G2, G3, G10, GX1, GH1, GH2, GF1, GF2, GF3, GF5, GH4, Panasonic AG-AF100 Mirrorless Digital Cameras, Black Magic Pocket Cinema Camera (BMPCC) 

hello panasonic lumix g7 is m3/4 mount, so the adapter ring could not work for panasonic lumix g7 

No, this adapter is for the older manual focus Minolta Rokkor MC and MD lenses. If you want to autofocus and aperture control you will need the Sony LA-EA4. (the lower cost Sony LA-EA3 will electronically connect A mount lenses but you will have to manually focus.) 

Focus peaking is controlled by the camera, not the adapter. You need to check your individual camera. My Panasonic G6 does have focus peaking active with this adapter and other adapters also. 

it will work with a3000 and a3500. use this adapter with minolta md or minolta sr lenses