You asked
Olympus om d e m5 mark ii vs panasonic lumix g7?
Both cameras use the same Micro Four Thirds sensor and the same lens mount, so the choice comes down to the body. The Olympus OM-D E-M5 Mark II is the one I'd pick if you can afford it. It's weather sealed, has a fully articulating screen, and stabilises every lens through the body.
The Panasonic Lumix G7 is the budget option. It has a viewfinder and 4K video, but no in-body stabilisation, so you'll want stabilised lenses for slow shutter speeds. It's very cheap used, which is its strongest argument.
If you shoot handheld in dim light or in bad weather, the Olympus is worth the extra. If you want a cheap body to learn on, the G7 does the job. For more on the system, see Micro Four Thirds.
Written by Claude from this site's pages.