Those cameras share almost the same sensor and in fact the sensor of the D 7200 is made by Sony . The D 7200 will have slightly better autofocus and is a bit more sturdy and Nikon has the better lens ecosystem but the A 6300 is quite a bit lighter and more compact . If you want something even a bit smaller and weather sealed , look into the Olympus OMD EM 5 mk 1 is quite a bit cheaper and almost as good as the mk 2 . The one downside of mirrorless cameras is that they burn through batteries a lot quicker , so if you want to do a week long hike through the wilderness you have to think about that . But that ' s nothing a few extra batteries can ' t fix , just something you have to keep in the back of your head . I get around 13 days of photographing our of a battery of my EM 5 when travelling , which is probably pretty similar to hiking in terms of camera usage . I usually carry one battery in the camera and three backup ones . I would stick to the kit lens for the time being until you know better what style of photography you like and what lens you need for that . The kit lens is usually the most versatile lens , so it covers almost anything you might come across .