Better shadows and no blurry face... I get it, it's a 4k render =D
View attachment 4983981
View attachment 4983983
edit: among other things like Knight said.
Blurriness is being caused by depth of field and aperture. It can really give the attention to a certain point in a picture/render but it can also mess it up.
The first picture really gives attention to the body and what she is doing. Second picture gives the attention to her as a whole person and not just her body and what she is doing. Both can work in a certain way, depends on what is going and what is trying to be told with this picture/render. If you really want to give the attention to what she is doing and her body, picture one should be used. If you want to draw the attention to her as a whole person, then second picture should be used.
I do use depth of field aswell. For example this picture. You can still see that she is in a class room, but I draw the attention to her intentionally and not the environment. This kind of renders could really work to give all the attention to the character, like the viewer is being distracted or being in a conversation with her. So I force people to pay less attention on the environment and more on to her.
It can also work the opposite, you can also take away the attention of a person. Like making the person entirely blurry and the background sharp, so you change the attention of the viewer. For example, when there is a scene where something happens behind a character. So, the blurryness has nothing to do with quality but how to change the attention of the viewer.
Depth of field isn't necessarily about quality, but drawing attention to a certain point. This could also work as part of the body. Making the head blurry while the rest of the body is sharp. This way you really give all the attention to the body. You can also do this in real life, put your finger infront of you and concentrate on your finger. Everything behind your finger becomes blurry. Now focus on the background, you will see that everything behind your finger will be sharp, but your finger blurry.
To proof that depth of field has nothing to do with quality, i've made these 8k resolution pictures. Don't mind the lighting and depth of field, it may not be perfect, I made these renders very fast, it's just to show what I mean.
I draw the attention to what is behind her.
I draw the attention back to her.