Hi,
Samsung galaxy s7 has a great camera even though resolution has been dropped from 16mp to 12mp, it has the capability to take sharper shots and in addition to that, it has an excellent low light performance As runner up, I would say LG G5 has still a great camera with has 24mp and Sony Xperia XZ with 23MP but still you'll be able to get a lot of detail in which would be perfect for nature shots.