Now you have changed your profile description from semipro to student i wonder if you know what you have bought,i dont know what Canon you had but your D7100 is a fantastic tool but will need input from you.I have in my gear a Nikon P610 and a Nikon D750,if i had taken the pictures you posted on both cameras with out any adjustments for the lighting situation i would have got out of the camera results better with the P610 than the D750.
This is because the D750 is designed like your D7100 to be a photographers tool,the P610 is designed for people that want to point it at something and take a picture,both cameras would see the same image but the P610 does work in the camera on the image that you would tend to do yourself when using a camera like the D7100.
Do a little research and plenty of practice (its free now you have the camera) and ime sure you will be over the moon with your results as your understanding improves.
