Originally posted by Digitalis I concur, I will also point out that the DOF you will see through the viewfinder is not what you will get in the final image - at least with lenses faster than f/2.8. For me, it is pretty easy to nail the focus at f/4 or at f/5.6 without special focusing aids but for f/1.2 lenses you either have to have the eyes of a hawk or be using live view or a customized focusing screen.
fortunately, I have very good eyesight.
+1 on Digitalis point about the DOF. I suspect that you might have used the maximum apeture on the kit lens at a range of maybe 3ft.
Just guessing at 35mm and f4 would give you depth of field of only about 4inches.
In the third photo it looks like you centred & focused on Gizmo's face and then recomposed the shot and changed this distance slightly with a result that with the very shallow DOF his face is now not focused exactly.
Coincidentally, I also have a ShihTzu named Gizmo with very similar colouring.
In poor light without an AF lamp it is quite difficult to focus on his face & eyes which are dark.
Luckily he stays still (sleeps) a lot which helps with longer shutter.
Here is 2 shots of Gizmo dozing off just now. The centre focus is on his lower eyelid
43mm @ f1.9 1/15s (about the slowest i can handhold)
43mm @ f8 1sec (on mini tripod, cable release)
at f1.9 the DOF is only about 4cm so if I recomposed the shot to get more of his body in the frame it would be nearly impossible to keep the original focus.
Having time to set up the shot I'd use a selectable AF point instead or manual focus.
Gizmo f1.9
Gizmo f8