Here we are comparing two cameras with different body types: Nikon P7800, which was introduced in November 2013 is a Small Sensor Compact camera with a 12.0MP 1/1.7" sensor whereas Sony A7 III, which was introduced in February 2018 is a Pro Mirrorless camera with a 24.0MP Full frame sensor.
Comparing an interchangeble lens camera to a fixed lens camera is a bit tricky but we will do our best to make this a fair comparison. Fortunately, you can't go wrong with any of these cameras as we rank them amongst Top 10 cameras in their classes. Nikon P7800 is ranked #1
out of 262 Small Sensor Compact cameras with an overall score of 69 whereas Sony A7 III is ranked #10
out of 38 Pro Mirrorless cameras with an overall score of 91.
Let's have a brief look at the main features of Nikon P7800 and Sony A7 III before getting into our more detailed comparison.