Sorry for spam your topic with off topic, but I ask since I have similar camera, and I can tell you that imgur is keeping original resolutions of picture ( it will not resize it ), and they have fantastic system for lowering a space and keep image quality, you can check it by uploading a pic to their site then download and compare to the original.
There is no chance that you use f2.7 if you have kit lens 18-55, since it is f3.5-5.6, you can go up anf change f stop to let’s say 16 or more, but you can’t go down below f3.5 it is impossible.
The pictures looks like to me like high value of iso is used that’s why I asked, and that is the case if you take pictures in automatic mode…