SteveR wrote:
Actually, the resolution increase is inconsequential. I have a D7000, however, and the mode (?) wheel is starting to turn too easily. The OP may be experiencing some of the same type of problems. This would be the reason to upgrade, not for a flimsy 8 mp. My daughter has the D7500 and it is a fantastic camera. If at all possible, I'd go for the 7500 over the 7200. Its low light capabilities are excellent as well.
Have to respectfully disagree with you on this, given the OP's stated usage of his camera. 50% more pixels (about 15% higher resolution in each direction, is of great impact with night sky photography. The difference will be immediately obvious, bringing stars that were otherwise not capturable at all into clear view. Even if that were not true, the extra three tops of sensitivity would still be a game changer for him. I agree that the difference would be less significant with other genres of photography, but not in this case.